字幕列表 影片播放 列印英文字幕 Dr. John P. Holdren: Well, good afternoon everybody. I'm John Holdren, President Obama's science advisor and the Director of the White House Office of Science and Technology Policy. It's my honor to be able to welcome you all to the White House and to launch this extraordinary event. We're here, of course, to talk about the release of the Third National Assessment of Climate Change Impacts on the United States. It exists. This is the 20-page overview. This is the 140-page highlights. The 840-page whole document is live on www.globalchange.gov and folks are invited to go there but not while today's speakers are talking. The assessment that we're launching today is distinguished by laying out with unprecedented comprehensiveness, disaggregation detail and clarity how the climate is changing across the United States, disaggregated by eight geographic regions, and also by various crucial sectors of the economy. Agriculture, fisheries, the oceans, energy, and so on. It basically is letting Americans know how climate is changing where they work and live, what impacts that is having on things they value, and how this picture is expected to evolve going forward and of course a very substantial emphasis on what can be done about it. We're providing what John Podesta this morning earlier called "actionable science." This is the theme. The President has also emphasized information that people can use to take appropriate action to reduce their vulnerability to climate change and to participate in the actions that reduce the emissions that are driving climate change around the world. I think that the findings of this extraordinary report, about which we'll be saying considerably more, are really the loudest alarm bell to date signaling the need for urgent action so that we can combat the threats and the risk we face from global climate change in this country. As I think you all know, President Obama has long recognized the urgency of this challenge and last June in a speech at Georgetown University on a sweltering hot day, appropriately enough, the President launched his Climate Action Plan. Three-part plan cutting carbon pollution in America, preparing our communities for changes in climate that already are on-going, and leading international efforts to address the challenge. Now, almost a year later, a lot has happened in executing on the commitments made in the Climate Action Plan. The President has directed the Environmental Protection Agency and the Department of Transportation to develop fuel economy standards for heavy-duty vehicles. Department of Interior has announced its permitting of the 50th Renewable Energy Related Project on federal lands during this administration. The Department of Energy has issued multiple new energy efficiency standards. Department of Agriculture has announced seven new climate hubs to help farmers and ranchers adapt their operations to a changing climate. The administration launched in this room and not very long ago a Climate Data Initiative bringing together extensive government open data and design competitions with strong commitments from the private and philanthropic sectors in order to develop data-driven planning and resilience tools for communities and I should say that Climate Data Initiative and the results of this extraordinary study we're launching today are coming together. All of the information that the study has developed will be available on the web again in user-friendly, accessible forms to provide people with the information they will need to reduce their vulnerability. Of course, as you all know, the President has instructed the Environmental Protection Agency to develop standards both for new power plants, which have already been put out there, and soon there will be standards proposed for discussion on existing power plants and their emissions of heat-trapping gases. So this is a lot of progress. We also announced just a couple of months ago a new strategy to reduce methane emissions that involve characterizing and quantifying the sources of methane emissions, committing to new steps to cut the emissions of that potent greenhouse gas, and outlining a set of actions going forward to improve the measurements so we can tell exactly how well we're doing. That, I would say, is what progress is supposed to look like and today's events around this extraordinary assessment are another big step. As I think probably everybody in the room knows, a critical piece of the President's Climate Action Plan is ensuring that we continue our steady pace to strengthen the science that informs and underpins the actions that we take to address the threats from climate change and ensuring that as we do that, we pursue the insights and the information that are most immediately relevant and useful to the people who need that information. We're talking about the folks who, in some sense, are on the front lines of climate change. The coastal property owners, the farmers, the fishermen, the city planners, the water resource managers, and others whose livelihoods, whose day-to-day decisions, and whose longer-term planning needs to be informed by the best data available. Knowledge about what is happening today in climate change, what's likely to come down the road, and what can be done to reduce vulnerability. And this assessment that we're releasing today, as you might imagine from its extraordinary length -- 839-pages, I think, on the web -- is a virtual encyclopedia of that essential information. The report was four-plus years in the making. It was produced under the auspices of the U.S. Global Change Research Program. 13 federal agencies and departments involved in that. Leadership came from NOAA and OSTP. The heavy lifting by a 60-person federal advisory committee. Writing team included some 300 individuals. I wouldn't even care to count the number of reviewers in probably one of the most extensive and transparent multi-stage review processes in the history of government reports. And that effort, that extraordinary effort which included experts from government at all levels, from academia, from business, from non-profits has really produced this exceptionally detailed disaggregated accounting of what climate change is already doing in every geographic region of the United States and the most effective sectors of our economy. The single most important bottom line that shines through all these hundreds of pages is that climate change is not a distant threat. It is something that is happening now, it is affecting the American people now in important ways. Summers, on the whole, are longer and hotter with longer periods of extreme heat. Wildfires in the west start earlier in the spring and continue later in the fall. Rain in many parts of the country is coming down in deluges and heavier downpours. People are experiencing changes in the length and severity of seasonal allergies and climate disruptions to agriculture and water resources have been growing. And, of course, again, key insight of this report: it's not the same everywhere. Climate change is not uniform. It is having different impacts in different parts of the country and that's why it's so important that this study based on advancing science over the past five years since the last one came out has been able to disaggregate these on-going and expected impacts regionally. When President Obama launched his Climate Action Plan, he made clear that the information in this new climate assessment would be used and it will be used to inform the efforts at the federal, state, and local levels to increase preparedness for and resilience against the impacts of changes in climate that can no longer be avoided. And I think it's very important to say that this report is not just a bad news story about all the impacts that are happening. It's a good news story about the many opportunities to take cost-effective actions to reduce the damages. I want to acknowledge a number of folks, including the stakeholders in this room, who have gathered to hear about this and who will be crucial actors going out and promoting, propagating, and implementing the findings of this report. We are grateful for all of your engagement, but I do want to thank four key individuals without whom this report would never have come to fruition. Kathy Sullivan the Administrator of NOAA and Under Secretary of Commerce whom you'll hear from later in the program for NOAA's key partnership in bringing this assessment to fruition, and I should mention as well her predecessor Jane Lubchenco who regrets that she couldn't be here but I spoke with her last evening and she handed the reins over to Kathy Sullivan from Jane's earlier involvement from NOAA in this extraordinary effort and again, without NOA's partnership support, needless to say also money, this study would not have been completed. Jerry Mellilo the Chair of the National Climate Assessment Development Advisory Committee affectionately called the NCADAC fac. Jerry's leadership in this endeavor ensured rigor, scientific integrity at every step of the way. You'll hear from Jerry in a moment as well. Cassie Jacobs who was the first executive director of the assessment whose vision and dedication really made this the most transparent national climate assessment ever and who kept the trains running on time for more than two years. Cassie was a great contributor and then Cassie's successor Fabian Loree who seamlessly picked up the ball and saw this report over the finish line with dedication, focus, and competence. I think to these folks and to the entire National Climate Assessment team, the whole NCADAC fac, the 300 authors, the even more numerous reviewers. I think we owe them a big vote of thanks and I want to lead that. (applause) Dr. John P. Holdren: And to the rest of you who are here today are partners at organizations and institutions standing ready to disseminate and communicate the findings of this report and its message that we need to take action and we can take action, I ask each of you here to absorb the energy and enthusiasm that we're generating today, carry it back, share it with your constituencies, share it with your communities. This is, in a sense, a new beginning of this effort to reach out all across the country and incentivize and organize the kinds of actions we need. Tell folks to visit globalchange.gov to get informed about what climate is doing in the regions where they live and work. Ask them to share that information further and invite them to share stories about what they're doing, what their communities are doing by using the hashtag #ActOnClimate. Now, I will wrap up, strap on my Master of Ceremonies hat, and proceed to the introduction of the next speaker who is none other than Dr. Jerry Mellilo. Jerry, I'm surprised to say given the enormous amount of work he had to put in to help bring this study over the finish line, actually has a day job. He is a distinguished scientist and Director Emeritus of the Ecosystem Center of the Marine Biological Laboratory in Woods Hole. And he also just about a week ago received the distinction of being elected to the U.S. National Academy of Sciences. So, Jerry, please accept my thanks and my congratulations and please accept the podium. (applause) Dr. Jerry M. Mellilo: I do set up for events as well, so I -- (laughter) Dr. Jerry M. Mellilo: Well, first let me thank you all for being here. This is a long-awaited day for many of the NCADAC members, authors, and all of our partners. It's been a team effort and we really appreciate all that you've done over -- I think it's been almost four years, not just two. So thank you very much. So, let me begin by repeating the headline that John issued for the report. Climate change, once thought of as a problem for the future, has moved firmly into the present. The take-home message is it's happening now and we need to pay attention. It is affecting us in our pocketbooks and on our land in every region of the United States. It is changing the lives of farmers, mayors, engineers, town planners, truckers, and foresters. This National Climate Assessment looks exclusively at the United States, breaking it down as John mentioned, into eight distinct regions. In contrast to IPCC's global assessments that look at North America as a single region. The National Climate Assessment digs deeper than global and national averages to reveal specific regional impacts that matter to people every day. This report is about what is happening to people in this country. With five more years of observed data since the last assessment and, by the way, a few of us -- Tom Carl, Tony Genados, and I, Rosina -- have been with this assessment process since the beginning. So, we've tracked its progress. This new report reveals specific climate-related changes and cumulative impacts already occurring in every region and in economic sectors such as health, agriculture, energy, water, and transportation. The report also reveals linkages among the impacts across sectors and this is something new in this report. For example, reduced water availability in an already arid region can increase competition for water resources among uses such as irrigation, electricity production, and the needs of the ecosystems that sustain us. And this effort of beginning to think about connections across sectors is something that we hope will continue because it's absolutely a critical area for study. This assessment is a result of a remarkably inclusive national process, as John mentioned. A lot of that thanks to Kathy. Author teams were made up of top experts from around the country and elsewhere. We had one Australian member on our team, as a matter of fact. Thousands of people were involved, participating in listening sessions, providing technical inputs, and producing and reviewing the report, including reviews by the National Academy of Sciences and other scholars, federal agencies, and the public. The multi-year process, as John mentioned, was guided by an independent federal advisory committee that included experts from universities, federal, state, and local government agencies, and industry including Monsanto, Chevron, ConocoPhillips, and Zurich Insurance. This committee reached unanimous agreement on the report's contents after very serious consideration. All Americans will find things that matter to them in this report from impacts in their own regions to those elsewhere that affect the air we breathe and our food, water, and energy supplies. We are all bearing the costs of the increases in extreme heat, heavy downpours, and higher coastal storm surges. For decades, we've been collecting the dots. Now we have connected those dots. The picture is clear and it is stark. Climate change is bringing serious challenges to our way of life, but that's only the beginning of the story. As John mentioned, there are opportunities and there's a lot that can be done about it. Across the country, Americans are already taking action. The good news is that many of the actions taken to reduce climate change and its impacts have a variety of additional benefits for our health and for our economy. It is not too late to change our emissions path and reduce future climate change and its impacts. The choices we make or don't make today will shape our future climate and the sustainability of our way of life. Now, I want to spend several minutes highlighting a few examples of what's new in the 2014 National Climate Assessment. This is a question we've been asked a lot by our friends in the press. The latest scientific analyses using satellite data since the early 1990s show that sea level rise has accelerated in recent decades in some areas of the globe, including our Atlantic Coast north of Cape Hadarus. With so many of our cities located on low-lying coast lines, this matter is of tremendous importance. For example, in 2012, the one-foot sea level rise that New York City had already experienced meant that the flood waters from Sandy surged further inland and did more damage than they otherwise would have. Coastal flooding is also affecting many other East Coast cities on a regular basis. Occasional flooding has become frequent in some of these cities and in others frequent flooding has become chronic. Responses to chronic flooding can be expensive. For example, Miami Beach is planning to spend hundreds of millions of dollars to reengineer storm drains in parts of the city to carry away sea water that backs up in the drains and floods the streets of that city. The links between climate change and sea level rise are clear. As heat-trapping gases continue to build up in our atmosphere, the oceans are absorbing more than 90 percent of the extra heat trapped in the climate system. This causes ocean waters to expand and, in addition, mountain glaciers are rapidly retreating which adds water to the oceans. The sleeping giant, however, in the sea level rise equation has been ice and the major ice sheets of Greenland and Antarctica. The latest science, again using satellite data, shows us that the giant is no longer asleep. Both of these ice sheets are now losing mass. How quickly they melt over the coming decades will determine whether we have an additional one foot of sea level rise or up to four feet and perhaps even more. Another major change in our climate brought about by human-induced warming is the increase in heavy downpours. This is clearly an area in which recent observations have been born out our previous projections. Our scientific understanding told us that a warmer atmosphere would hold more moisture and we measured that and, indeed, it is happening. We also predicted that the increase in atmospheric water vapor would mean that more of the rain would come down in heavy events and now we've seen that happen. Some regions, like the Northeast and the Midwest have seen very large increases in the amounts of rain falling in the heaviest events. In the future, even areas that are projected to see decreases in total amounts of annual rainfall are expected to see significant increases in the proportion of that rain coming in very heavy events. Okay. Another thing we've seen is that the areas that have had big increases in precipitation have also had increases in flooding. River flood magnitudes over the last 90 years have decreased in the Southwest and increased in the Great Plains, parts of the Midwest, and from the northern Appalachians into New England we are also seeing increased flooding. The map on this screen shows increasing trends in floods and green and decreasing trends of floods in brown. The magnitude of the floods is related to the size of the triangles. Of course, global warming also means that our nation has gotten hotter on average with some areas seeing bigger changes than others. But it's not the average that we notice so much but rather the extremes. In recent decades, we had fewer really cold days and more really hot ones and that has had many important impacts. One of these impacts has been on the amount of energy we use for heating and cooling. First, the good news -- we've needed less energy for heating. But now for the bad news. We've needed a lot more energy for cooling. Heating energy comes from natural gas, heating oil, wood, electricity, and other sources. But cooling is all electricity. That means some of the big new peaks in demand for electricity for air conditioning in the future are going to present serious challenges for our electric utilities. The new information in the assessment advances our understanding of the challenges that climate change presents for the American people. The assessment provides Americans with a firm scientific foundation upon which to build wise responses for themselves, their communities, and the nation. Thank you. (applause) Dr. Jerry M. Mellilo: Okay, we are now going to begin our first panel. John was going to introduce Dr. Gary Yohe who is the moderator of the panel from Wesleyan University. He has been called away sooner than he thought, so I'd like to ask Gary and the panel to join us up here on the podium and we will begin with a short set of statements by each of the panelists and then we will take some questions from our stakeholders. So, Gary, I'm going to turn this over to you. Dr. Gary Yohe: Thank you, Jerry. Thank you all for coming. Our first panel talks to specific findings in the Third National Climate Assessment and I think what you will take away from this is that this panel confirms the specific conclusion of the NCADAC and the Third National Climate Assessment that, indeed, every American will find things that matter to him or her in this report. With that, I will ask each of the panelists to introduce him or herself and you have three minutes. Dr. Don Wuebbles: Thank you, Gary. I'm Don Wuebbles. I'm a professor at the University of Illinois. I was involved in the assessment in a number of different ways, including heading the chapter, collating the chapter on the climate science called "In Our Changing Climate." What I'm going to do is talk a little bit about that evidence for the climate that's changing, that the climate is changing, and why we see human activities as being the primary cause of that change. First of all, there are many indicators that the climate is changing. Each of the last three decades has been successfully warmer as the Earth's surface in any preceding decade since 1850. Overall, the world has seen an increase of about one and a half degrees Fahrenheit increase since the late 1800s. The U.S. has seen a similar temperature increase over this period. Most of this increase has occurred since 1970. The most recent decade was the hottest on record both nationally and worldwide and 2012 was the hottest year on record in the continental United States. All U.S. regions have experienced warming in recent decades but the extent of warming has not been uniform. In general, temperatures are rising more quickly in the north. Meanwhile, average annual precipitation over the U.S. has also increased, although there are important regional differences. Trends in some types of extreme weather have also increased. Prolonged periods of high temperatures have increased in many locations. Heavy downpours are increasing nationally over the last three to five decades, especially the Northeast, Midwest, and Great Plains, as Jerry showed. Some regions like the Southwest and Southeast have seen an increasing trend for droughts while others such as the Northeast and Midwest have seen an increasing trends in floods. Natural drivers of climate cannot explain the recent observed changes. These changes are not due to the sun, they're not caused by natural cycles. The majority of the warming at the global scale for the last 50 years can only be explained by the effects of human influences, especially the emissions from burning of fossil fuels and from deforestation. This conclusion that human influences are primary driver of recent climate change is based on multiple lines of evidence. Independent evidence. One is the fundamental understanding of how certain gases trap heat, how the climate system responds to increases in these gases, and how other human and natural factors influence climate. Another reason comes from reconstructions of past climates using evidence such as tree rings, ice cores, and corals. These show that global surface temperatures over the past several decades are clearly unusual with the last decade warmer than any time in the last 1,300 years and perhaps much longer. Another line of evidence comes from using models to simulate the climate of the past century. Natural factors like the sun and volcanic activity would have tended to slightly cool the Earth in the last 50 years and other natural variations are too small to explain the amount of warming. Only when the human influences are included do the models reproduce the warming observed over this time period. Thank you. Dr. Tom Karl: Thank you, Gary and Don. My name is Tom Carl. I'm the Director of NOAA's National Climatic Data Center and I also Chair the Interagency U.S. Global Change Research Program. Well, today I'm going to try and paint a picture for you of expected changes in climate based on the present path of global greenhouse gas emissions. Much of this information that I will talk about -- not all, but much is based on improved climate models, particularly compared to previous assessments. We've got more models with higher resolution, more physical processes represented. So let me just highlight a few aspects of future climate expected by the end of this century. First, for temperature, it's going to be hotter. On average about 8 degrees Fahrenheit warmer. Compare that to the warmth of the increasing warming temperatures we've seen and the order of a degree and a half since the turn of the 20th century. And temperature changes up to 15 degrees warmer in Alaska. There will be fewer cold extremes and many more hot extremes. There will be fewer frost days with a frost-free season increasing between 30 to 70 days, depending on the location. For precipitation, the moist areas will get wetter in the order of 10 to 30 percent. The arid areas will get drier in the order of 10 to 20 percent. As a result, soil moisture will be reduced in much of the country, particularly in the Southwest and the central U.S. Both due to less precipitation and hotter temperatures increasing evaporation rates. To go along with this, a number of consecutive dry days are expected to increase while at the same time the frequency and intensity of extreme precipitation events is expected to increase across much of the continental U.S. up to four times more than what we see at the present and as much as six times greater in Alaska. The environment for severe thunderstorms is expected to become more favorable in the future. The most intense hurricanes are expected to become stronger and more frequent with rainfall rates increasing in the order of 20 percent near the center of the storms. For sea level, global sea level rise is expected to increase in the order of one to four feet with even greater rises where land is subsiding. For sea ice, summer sea ice is expected to disappear by 2050 of this century. The bottom line. The current path we're on will result in a climate that is far different than anything that this nation has experienced. Thanks. Dr. Radley Horton: Thanks, Tom. My name is Radley Horton and I'm happy to speak with you today about the findings of the Northeast region, one of the eight regions covered by this report. In the Northeast, we've seen sea level rise of about a foot on average in the past century. We've also seen temperatures increase by almost 2 degrees Fahrenheit over the past century. And these heavy downpours that we've heard about are now producing on the order of 70 percent more rainfall than they were just half a century or so ago. These climate changes are already leading to impacts throughout the Northeast and beyond. When we think about the impacts of sea level rise, the central part of that, central range of that projection that Tom just mentioned, two to three feet, would more than triple the frequency of coastal flooding throughout the Northeast and beyond, even if storms did not become any stronger. For some places like New York City, what had been a 1 in 100 year flood event becomes something that you expect during the lifetime of the typical mortgage. Even if storms do not become any stronger. Within the Northeast, we have critical infrastructure right along our dense coastline. Everything from our iconic transportation networks, I-95, Amtrak, commuter rail networks, to electric grid. Substations right along the coast. Waste water treatment plants along the coast. All increasingly vulnerable as sea levels rise. This puts populations at risk, it jeopardizes commerce, human safety, and as we heard leads to expensive repairs as well. As we saw during Hurricane Sandy, all of these infrastructure networks are connected. If one part of that system goes down, if we have electrical grid failures, it cascades into other systems. It's harder to pump water out of subway station, for example, when the electric grid goes down. Another important risk to highlight is the danger associated with more frequent heat waves as temperatures rise. We know that the very young, the elderly, and some of our disadvantaged populations are most vulnerable. As temperatures rise, cities have unique vulnerabilities. Air quality is often poor when those temperatures are really high and there's a greater risk of power going out as we see increasing demand for air conditioning. But it's not just the cities that are going to be vulnerable in the Northeast to heat in the future. As temperatures rise, some of the northerly areas that in the past haven't needed air conditioning as much are going to increasingly be relying on it. Quickly, too, intense precipitation events pose some unique hazards for some of our inland and rural regions. If we look at some of the mountainous parts of the Northeast, a lot of the human populations, transportation, agriculture is concentrated in valleys. With more of those heavy rain events, there's a risk of more flooding. In general, whether you're talking about cities or rural areas, more combined sewer overflow events, more failure of sewer systems. A public health hazard throughout the Northeast and beyond. But it's important to highlight that we have opportunities as well. The Northeast, whether from cities or states have shown leadership in thinking about these climate risks. We've seen ambitious efforts to begin to reduce greenhouse gas emissions and we've seen steps to adapt to these climate changes as well. In general, though, implementation is at early stages but fortunately this report offers a range of strategies to help close those gaps. Thank you. Dr. Kim Knowlton: Thank you, Radley. And everyone. It's a real pleasure and honor to be with all of you today and my colleagues here. I'm Kim Knowlton. I was one of the authors on the Human Health chapter and I just want to that when we talk about public health, climate change becomes very personal. We've always thought of climate change as something that happens to someone else, but now we know it's happening to us right now. And there's a few ways that climate change is fueling some of the most important kinds of extreme weather events that really affect people's heatlh. My colleagues have mentioned extreme rainfall events, those big deluges that just send lots and lots of rain. In fact, in the Northeast where I live, where I'm from, there's been a 71 percent increase in the amount of rainfall that comes down in the most extreme rainfall events. In the last 50 years. That's already happening. The hospital where I was born in upstate New York in Binghamton was flooded up to the first floor in 2006 by rising river waters after torrential rains. And those kinds of rainfall events are projected to increase five-fold in the future with climate change. In our children's lifetimes. Radley mentioned heat waves and those are a big concern being fueled by climate change again. And extreme heat also increases drought risks, wildfire risks. Those affect people's health. Now, heat is not just an inconvenience, it can be lethal. It can send thousands of people to emergency rooms as it has done in the past. Another dimension of this is that there's millions of people in our country who are more vulnerable to the effects of heat and other climate health effects. That includes millions of people age 65 and older. And we're all getting older, as nature has it. Our youngest Americans, people living in economic disadvantage, some communities of color. People who already have breathing, heart, lung problems. So, people who are already struggling to stay healthy are going to find that's more of a struggle as climate change continues. An example. Today is World Asthma Day. There's 26 million people in the United States that have asthma. Part of our concerns are that rising temperatures worsen air pollution. Air pollution from ground-level smog to fine particles to pollen can trigger asthma attacks. Rising temperatures are also making the length of time that plants produce that pollen longer. Already since 1995 there's been a two to three week increase in the length of ragweed pollen production season in a swath of states in the central U.S. and Canada. Now, that matters to people who have asthma. But we have huge opportunities as my colleagues have said to make improvements that affect us all and the assessment report really focuses on those opportunities. An example. If we reduce the amount of fossil fuels we use to get energy, we stand to one reduce air pollution that we generate from that activity right now. That's a win for health today. Two, we get a double benefit because we can reduce heat-trapping carbon pollution emissions. That's a win for our kids, for the future. And three, if we step away from taking every short trip to the school, to work, to business in cars and substitute biking, walking paths, more public transit. We get a chance for more physical activity. That's triple. We stand to establish all kinds of wins for public health. So, we're really at this crossroads now in terms of using the assessment and the body of science that we've collected thanks to the work of many scientists to make informed decisions about where we go from here and trying to create a future that really has a human face on it and that's healthier and more secure. So, I'm really honored to be part of that conversation with my colleagues and with all of you. Thank you. Dr. Gene Takle: Thank you, Dr. Knowlton. I'm Gene Takle, co-author of the agriculture chapter. An overarching theme of the agriculture chapter is that crop and animal agriculture producers in the U.S. are already facing increased challenges from changes in climate. To put this into context, U.S. agriculture is very diverse with most regions having crops and animals that are highly adapted to local climate conditions. Local temperature, rainfall, and soils dictate what crops are grown and where. Likewise, animal agriculture is practiced where climate allows grazing opportunities, animal comfort, and low disease potential. Specialization and intensification that have increased productivity have also tightened the relationship between agriculture and climate. In the Midwest, where I'm from, we have more rain coming in the first half the year and less in the second half. We have a 40 year trend of increased extreme rainfall events that are delaying or preventing the planting of soybeans and corn. There's also a rising concern about the increase in soil erosion accompanying these extreme rain events. California producers are facing a different but analogous set of challenges including drought and heat impacts on vegetable production. On the other hand, there's been a decline in the last 50 years in the number of chilling hours necessary for fruit trees and grapes to maintain a high production. Cherry trees, for instance, that require at least 900 chilling hours between growing seasons no longer meet the minimum chilling requirements in some parts of California due to warmer winters in the last half century. Many parts of Texas and Oklahoma in 2011 experienced more than 100 days over 100 degrees Fahrenheit with both states setting new high temperature records and rates of water loss were double the long-term average, depleting water resources and contributing more than $10 billion in direct losses to agriculture. These trends in temperature and precipitation that pose threats to agricultural production observed over the U.S. are likely to continue and become much more severe under the high carbon emissions scenarios. These trends are consistent with the global trends of dry regions getting drier and hotter and wet regions getting wetter and more humid. All such trends pose threats to U.S. agriculture. Farmers are beginning to connect the dots and recognize that local climates underpinning their multi-generational livelihoods and rural agri-business communities are changing. They are forced to seek increasingly more costly strategies to adapt to these changes in order to maintain profitability. By mid-century under current climate emissions trends, it is unlikely that adaptation strategies will be sufficient to avoid the negative impacts to most U.S. crop and livestock production. Thank you. Dr. Susanne Moser: Thank you, Gene. Good afternoon. My name is Susanne Moser and it's my great honor to introduce you to the coastal chapter. The essence of the story that we're trying to tell in the coastal chapter is actually quite simple. It simply says what happens to our coast will happen to our nation. More than half of the American public lives in a coastal county producing nearly 60 percent of gross domestic product. 9 out of 10 consumer products that you use in your house today and your home came through one of our nation's ports. If you put gas in your tank, if you bought seafood today for dinner, well then you are inextricably linked to what happens at our shores. It's these and many other facts like that that make it clear no matter where you live in this country, you will feel the consequences of climate change on our shores. Let's say you don't live in Portsmith, New Hampshire or northern Virginia or Charleston, South Carolina where the streets already regularly flood during particularly high tides. Say you don't live in Cape Cod or on Hawaii where the salt water already pushes into coastal ground water reservoirs that people depend on. Or say you don't live in the bayous of southern Louisiana where every 24 minutes, one football field worth of land is lost forever to the combined impacts of sinking land and rising seas. Well, then it might come as a surprise to you that climate change is no longer a hypothetical threat in some distant future. As we speak, it already leads to intermittent disruptions for businesses and everyday lives. It's already an expensive headache for those maintaining our coastal roads, airports, and sewage treatment plants. Sea level rise is already eroding away invaluable beaches and dunes and wet lands and with them the habitat for countless animal and plant species. And as that sea level continues to rise, these issues will grow from an intermittent to a chronic problem and during coastal storms to life-threatening dangers. In small coastal villages in Alaska as much as in some of our biggest, most vibrant cities like LA, Houston, or as we saw in Sandy, in the Big Apple. So, in our chapter we show how the lifelines like roads and bridges, energy infrastructure and water pipes are a growing risk from sea level rise and storm surges. We show how nationally important assets are at risk of being repeatedly disrupted by storms and floods. We also show how many of our most vulnerable populations are more exposed to coastal risks and have fewer options to adapt. And then how coastal habitats that we love and need are at the tipping point of irreversible damage. But what our chapter will also tell you is that coastal managers are actually beginning to recognize these dangers and are working hard to find solutions. Clearly, there are no simple, easy solutions, but then again America didn't become a great nation because it was easy. What they show us is that we can with hard work reduce these risks, get better prepared, and work together with foresight for a safer future. Thank you. Dr. Gary Yohe: Well, thank you all. I've been looking out. It's a little hard beyond those lights. Not a lot of smiles. (laughter) Dr. Gary Yohe: One of the questions that I thought I would ponder and ask my colleagues as we maybe collect some questions from you all and once you're done, I will actually answer it myself, but in 15 to 30 seconds, what keeps you up at night? Dr. Don Wuebbles: So, this is Don Wuebbles again. I live in the Midwest. I don't live in the coastal areas, so as bad as all those coastal things Suzy was talking about frighten me as much as all of us. The things that really worry me, keep me up at night is the concerns about severe weather and it's not what we already know, it's what we don't know. We're trying to learn exactly what's happening with severe thunderstorms in order. Are we likely to get more and stronger tornadoes in the future? Are we going to have more ice storms? Are we going to have more hail? We don't know those things yet. We have some pieces of evidence that are pointing in certain directions that they could be -- that things like lightning or tornadoes could become more intense. But we're still in early stages of the research. And so I worry about the research that I and my colleagues need to do to really learn what needs to be learned there. Dr. Thomas Karl: Thanks, Gary. A couple things come to mind. For me it's those events that are feasible but not so likely. So, what we talked about here today are those events we have considerable confidence as we continue the path we're on will eventually occur. But there are a number of events that are feasible but perhaps not so likely, but if they do occur, they could be quite a surprise. Jerry mentioned them earlier. Jerry Mellilo with respect to the collapse of the major ice sheets. Antarctica, Greenland. Another one is feedback from the melting of permafrost, rapid releases of methane and carbon dioxide have been stored in the ice for many, many centuries. Pretend an additional burden on the atmosphere with respect to greenhouse gases that could actually accelerate the changes that we've already been talking about. Dr. Radley Horton: So, following up along a similar vein. I worry about loss of sea ice in the Arctic. We've seen by 2012 about a 50 percent reduction in the area of late summer sea ice and about a 75 percent reduction in the volume. One of the reasons that's a cause for concern is that that's a faster rate than the models projected when run with increasing greenhouse gases. It raises the possibility that while climate models are absolutely our best tools for projecting the future instead of creating this bound of possible outcomes, it alludes to things we heard from Jerry, things we heard from Tom that at this sort of tail risk, worst case scenarios, there are possibilities potentially outside of what climate models suggest that we need to be thinking about as well when we protect our long-term concerns. Dr. Kim Knowlton: Okay. What keeps me awake at night? I worry about two things that come to mind. Cumulative effects on people's health of one storm then another storm, then poor, poor air pollution in communities that are already challenged by being next to places, facilities that emit air pollution over time. Then there's a heat wave. I worry about people's resilience both economically, health wise, and mentally, spiritually. Even strong people have a tough time being responsive and on their game with event after event after event and that's what climate change is doing. Creating multiple events. The second one is multiple system failure. We depend on our cities' hospitals and roadways and electrical power to provide air conditioning when it's hot as heck outside. And when it goes down, everyone is in the middle of a heat wave with very little way to escape or, in the case of a storm, it really compromises a way to get to safety. So, I think that those are real opportunity areas for us to look into and keep people healthy. Dr. Gene Takle: I worry about food security, both globally and in the U.S. because social unrest happens very quickly under food insecurity. And I've talked about the production side of it, but that's only one part of food security. It involves transportation, it involves processing, it involves storage. And so, any breakdown in any of those from any of the factors that we've already talked about could lead to food security which could lead to social unrest very quickly. Dr. Susanne Moser: Thank you. The question, Gary, that you ask "What keeps you up at night?" is the translation that we use in the coastal chapter actually to get at what are we most vulnerable to? And that is a mixed of really what is coming from climate change but also what is it meeting on the ground. It's the social vulnerability. It's our economic capacity to deal with it and so, if you just look at sea level rise, you might say well, Miami is right at the front lines. But Miami has some pretty significant capacity to deal with it. I'm actually much more worried about the small communities that are facing similarly big risks but don't have the power of Mayor Bloomberg, Anna-New York City, and not of LA and not of the big cities. So, that is really the combination that keeps me up at night. Dr. Gary Yohe: Thank you. I promised that I would answer it as well, and it really feeds off of what Suzy just said. What keeps me up at night is a persistence across the population not to recognize that the old, normal climate is broken and we don't know what the new normal climate is going to be. And that that lack of recognition and the inability of this community and decision makers to communicate those risks to individuals unnecessarily puts economic assets at risk, unnecessarily puts human lives at risk, unnecessarily puts ecosystems at risk. And when I wake up in the middle of the night, that's what worries me. Okay. What do you see as bright spots in how we are responding to climate change at the federal, state, and local level? Actually, I just got these. But I actually think that that's the point of the second panel. How can the NCA help decision makers? That is as well. (laughter) Dr. Gary Yohe: What is the estimated increase in health care costs? Do we have any cogent estimates? Dr. Kim Knowlton: We have taken a look -- not in the National Climate Assessment per say, but in an important study that is cited and referenced. We want the assessment to be a really important working foundational document. There was a study that looked at six events of types that climate change is going to increase in frequency or extent or the duration in the future, but these are six events that happened today. Have already happened in the last decade between 2000 and 2009. The health-related costs were $14 to 40 billion. And those health costs don't typically get included when we estimate very important infrastructure and roadway and building costs from these extreme weather events. So, I think that that's an important dimension to consider. Dr. Gary Yohe: Okay. I just got a great balancing question. We heard the concerns of the panel. What gives them the most hope that we can meet the challenges of climate change? And I think this is only fair. Dr. Don Wuebbles: Oh, I agree. I give a lot of public talks about climate change because I feel it's important to put my time in to explain to people why this is such an important issue. I worry about our children and our grandchildren and the future they're going to face. But in my talks I usually talking about our hope for the future. We as Americans have shown through history that we know how to solve problems and I think we can solve this. We can deal with it, but we have to make that choice and get on with it. Dr. Thomas Karl: So, I think there's a great advantage in this issue and that is this nation is very weather-conscious. We hear about it every day. It's always in the picture. And it's quite clear that we are experiencing changes that quite literally are unprecedented in this nation's history. As more people see these changes, they are talked about. The President did a talk about it today with a number of TV weathercasters and broadcasters. I think there's very, very much hope there in terms of trying to reach out and education the broad populace on the problem we face and how we can solve it. Dr. Radley Horton: I just quickly echo that I do think we may be sort of slow to get going with change, but I think if you look at some historical precedents, once we get started, change can happen quickly. And we can already see throughout the Northeast and beyond examples of how cities are dealing with heat events, planting more trees, getting air conditioners in some cases, and cooling centers to the most vulnerable populations. Having heat wave action plans. Facing the climate risk, elevating critical infrastructure, elevating houses, having discussion about coastal zone planning. Even more mundane things. Increasing the size of culverts, drainage pipes. When they're undergoing sort of a routine maintenance and repair and just adding in a factor to account for these larger increases and expected extreme precipitation. Dr. Kim Knowlton: Well, at the risk of being idealistic, the fact that everyone here is definitely interested in this issue and there's so much attention to it because it affects everyone. Climate change affects all of us, and I think there's a rising sense of participation and we're all in this together. And I think that recent events with extreme weather have brought that home. No one likes to think about very tough problems when there aren't solutions and I actually think that the assessment report provides information that's really accessible about opportunities that we have to make decisions that are going to get us to a better place and hopefully it will inspire leadership at every level to step forward and be part of that. Dr. Gene Takle: I'm excited about what I see in terms of local food systems and the more interest in local foods and reducing the number of food miles. Do we really need strawberries from Argentina in the middle of January or can we go back to some of the excitement I remember as a child growing up of getting fruit in season because it was such a rare thing. Can't we go back to some of those and, in the process, reduce food miles and perhaps even increase our nutritional value? Dr. Susanne Moser: The thing that gives me the greatest hope are you all. And the people that I work with on a regular basis in my day-to-day job. It's the people that are leading the efforts in coastal communities. It's the people who are willing to step outside the colored lines and draw outside those and do something new. Work together across their disciplinary lines, walk across to the other division, to the next apartment, to the next community down the stream. That, to me, is the greatest hope and it's one thing I can tell you we don't do a good job yet of putting into climate models. The human spirit is not well modeled -- (laughter) Dr. Susanne Moser: -- and I will tell you it is the most important factor in getting us off of where we are right now and onto a different path. Dr. Gary Yohe: Okay. We're getting close to the end of time. One last question that I got and I think it's directed to me, so I'm going to try to answer. Can you speak to the economic costs associated with climate change from the perspective of what the National Climate Assessment has taught us? And what I can say is that there will be costs of climate change. We're already experiencing them. They will get larger and they are calibrated not always in dollars and cents but in human lives and ecosystems. Whatever the appropriate metric. There will be some costs to the responses that we think about. Reducing emissions of greenhouse gases or increasing resilience and preparedness to future climate changes. But what you find over and over again from the specific examples that are located throughout the assessment is that the costs of not doing anything is much higher than the cost of doing something, and that the cost of not doing something only increase dramatically over the next few years, over the next decade, and into the future from there. So, with that, I thank you for your attention in panel one and Dr. Holdren is back. (laughter) (applause)
B1 中級 白宮關於國家氣候評估發佈的活動 (White House Event on the National Climate Assessment Release) 236 17 richardwang 發佈於 2021 年 01 月 14 日 更多分享 分享 收藏 回報 影片單字