字幕列表 影片播放 列印英文字幕 Glaciers are melting, sea levels are rising, droughts are more frequent, extreme weather events more common-- This is climate change in action, and you've heard it all before. But a major report just came out that looks at how close we are to this irreversible damage, and it's looking bad. Real bad. Back in 2015, the world's leaders came together to solidify a plan to combat climate change. The resulting Paris Agreement set a goal to hold “the increase of global average temperature to well below 2 degrees celsius above pre-industrial levels” and added the intent of “limiting the temperature increase to 1.5°C. But now, in October of 2018, the UN Intergovernmental Panel on Climate Change, or the IPCC, compiled the results of over 6,000 scientific studies and released a new report. The main takeaway? At our current rate, global average temperature is likely to rise 1.5°C between as early as 2030.This means, we only have 12 years to make drastic changes, or we'll miss our target. The difference between 1.5 and 2 may seem small, and and it's hard to imagine how half a degree could make much of an impact. But using climate models, scientists can predict what that half a degree actually means for our planet. And, well, it means a lot. First there's the arctic. At 1.5 degrees warming, arctic sea ice will still last through most summers, but at 2 degrees, ice-free summers become 10 times more likely. This would not only be devastating for arctic wildlife, but would reduce the albedo, or the amount of light being reflected away from earth, causing even more warming. Ice melt coupled with rising temperatures means sea level rise. At 1.5 degrees warming, average sea level rise could be somewhere between 26 and 77 centimeters. At 2 degrees, that range could go up a whole 10 centimeters. That change could expose about 10 million more people to harmful flooding than if warming stays at 1.5. A warmer world also means that fresh water will become even more scarce. At 1.5 degrees, severe drought will likely affect 350 million people, but at 2 degrees, that number grows to about 411 million people. Heatwaves get worse, too. At 1.5 degrees, about 14% of the world's population will be exposed to severe heat waves, and at 2 degrees that number more than doubles, raising to a whopping 37%. Then, there's the coral reefs. At 1.5 degrees warming, 70-90% of coral reefs die. At 2 degrees, that number grows to greater than 99%, meaning virtually all coral reefs will disappear. This would be devastating to marine biodiversity and affect nearly 500 million people who rely on them for storm protection, food, jobs and recreation. If none of this phases you, a separate study published in Nature looked into how many people could die from that half degree rise. They found that due to air pollution alone, an additional 150 million people could die if we hit 2 degrees. And that's not even including the likely deaths by heat wave, drought, and famine. So what can we do? Well, the report makes it clear that the pledges made in the Paris Agreement will not be enough. It not only states that these goals won't keep us under the 1.5 degree mark, but that they could result in a warming of THREE DEGREES by 2100. A whole degree higher than what the world decided should be an upper threshold. To prevent this, the report states that we have to drastically reduce CO2 emissions well before 2030, and at faster rate than we ever have before. And while highly unlikely, scientists are stressing that keeping warming to 1.5 degrees is still possible. Projections suggest it would require CO2 emissions to take a nosedive and then operate in the negatives towards the end of the century. While there's no definitive plan yet, it would likely involve steep, across the board investment in renewables, the electrification of huge energy sectors that currently run on fossil fuels, and rapid advances in negative emission technologies that can suck carbon out of the air. Among other things-- like a carbon tax, a world-wide reduction in meat consumption, a decline in population growth, and maximized global energy efficiency. So yeah, it will take quite literally everything we've got, but it's possible. So what do you think, can we do it? Negative emission technologies could be a big player in our fight against climate change, but how feasible are they? We've got a video coming about about that soon. And to stay up to date with all the latest climate news, make sure to subscribe. Thanks for watching Seeker.