字幕列表 影片播放 列印英文字幕 This video is sponsored by Brilliant. In July 2012, a ship floating off the coast of British Columbia dumped 100 tons of iron slurry into the pacific ocean. With this massive injection of iron into the water, the crew, led by the eccentric entrepreneur Russ George, sought to create an algae bloom that would not only capture carbon but also spur the growth of salmon in nearby coastal fisheries. Fisheries that the Haida Nation hired Russ George to replenish. The result? A surge in salmon population the year after that patch of the ocean was fertilized with iron, and for Russ George, a firestorm of scientific and public backlash that illuminated the ethical, political, and ecological consequences of these seemingly silver bullet solutions to climate change and environmental collapse. The Russ Georges of the world continue to champion these magical techno-fixes as the path towards stopping climate change. So today, I'm going to unpack the consequences of these silver bullet solutions with two questions: Are silver bullet solutions realistic? And if they aren't, why do we continue to pursue them? Silver bullet climate innovations span the sci-fi-sounding spectrum of ideas from launching mirrors into space to the holy grail of clean energy: nuclear fusion. That's my fellow YouTuber Adam Levy, who runs the amazingly informative channel ClimateAdam and also happens to have a PhD in Atmospheric Physics. As Adam just mentioned, there are a lot of seemingly magical fixes to climate change, but today we are going to narrow in on two specific case-studies of these climatic “solutions” that help illuminate how and why we seek out fast-fixes for climate change. The first is bioenergy with carbon capture and storage also known as BECCS. Simply put, this technology transforms organic materials such as paper pulp, crops, or bycut from logging industries into energy via fermentation, combustion, or gasification. There are a range of technologies under the BECCS umbrella, but all seek to capture CO2 released during the energy creation stage then store that captured CO2 into underground aquifers or dried up oil wells. Thanks to the bioenergy in BECCS, CO2 is absorbed by the plant matter fuel as it grows. And when this fuel is burned, thanks to the carbon capture and storage, this CO2 is - well - captured and stored. The appeal is that BECCS technologies take more CO2 out of the air than they put in. And because we've delayed cutting emissions for so long roughly 90% of IPCC projection scenarios point towards significant use of BECCS to help us remain below 2.0° C. In theory, BECCS sounds like a great plan. After all, you're stopping emissions at the source and the biomass that you use is also capturing carbon. In other words: negative emissions. But, in practice, BECCS is not the silver bullet solution that it seems to be. One large obstacle for the large-scale implementation of BECCS simulated in the Intergovernmental Panel on Climate Change's scenarios is land use. According to a briefing from the Grantham Institute, models that use BECCS to remain below 1.5°C could require the equivalent of 25-80% of our current cropland in order to grow enough biomass to replace current fossil fuel production. Even if we used just 20% of our current cropland, we would have to use the equivalent of all the land in Australia to satiate BECCS's demand for biomass. Such huge land requirements would inevitably drive land use change, potentially resulting in deforestation, biodiversity loss, and loss of carbon sequestration from natural sources like trees. Granted this is very much dependent on context. In the short term countries like the U.S., which has a comparably mature bioenergy infrastructure, could use existing agricultural and logging waste to fuel this endeavor. But in order to scale up BECCS in the long term in line with the IPCC scenarios, this technology would require a massive amount of land for biomass specific crops. The levels of BECCS in these simulations would require much more than agricultural waste alone. Eventually, farmland will need to be diverted to specifically grow crops for BECCS use, which means additional fertilizer use, additional trucks transporting biomass to energy plants, and a heavy strain on fresh water resources to the tune of 0.72 to 24.4 billion metric tonnes per year. To put that in perspective, global agriculture's total water consumption right now is close to 8 billion metric tonnes per year. And growing fuel instead of food could cause at least as many problems as it solves. It's important to keep in mind that, like almost all silver bullet solutions, BECCS has yet to be tried at a massive scale. Although we shouldn't write it off completely for its shortcomings, we need to recognize it's easier to implement it in a climate model than it is in reality. There is still a lot we have to study and figure out before we begin to heavily rely on it. That being said, out of all the silver bullet solutions proposed in the last couple of decades, BECCS is one of the more reasonable and achievable. But there are some that are straight out of a sci-fi movie. With that we turn to Solar Radiation Management or SRM. In short, solar radiation management is used to describe a range of methods that seek to reflect sunlight back out of the atmosphere to reduce global temperatures. SRM solutions include reasonable and achievable ideas like reflective paint on roofs but they also incorporate proposals like the highly imaginative space mirrors that would orbit around the earth. And one solution in the middle of that spectrum is stratospheric aerosol injection. Essentially this silver bullet solution attempts to mimic the natural phenomenon of volcanic eruptions by injecting sulphate aerosols into the upper atmosphere. These tiny molecules would create a reflective blanket around the Earth, artificially cooling the climate. But, does this method actually work? Yeah, it seems like it would, although no one has conducted a real world experiment with stratospheric aerosol injection. But researchers can study natural experiments after big volcanic eruptions. The aerosols from these do indeed cause the Earth's temperature dip for a year or two. But even though these aerosols would be pretty cheap to manufacture and inject, this cooling would come with substantial hidden costs. He's right, according to one paper on stratospheric aerosols, the cooling effect could cause a global shortage of rainfall, especially in summer monsoon regions, droughts, increased air pollution, acid rain, and the possible depletion of the ozone layer. Sulfate aerosols only stay in the atmosphere for 1-3 years, which means that constant injections are needed to maintain the cooling effect. If the method was ever suddenly halted, one study predicts we would experience rapid temperature and precipitation increases at 5–10 times the rates of our current global warming trend. Considering that our current governing bodies can barely agree on emissions targets, it's hard to imagine the world agreeing on a consistent delivery of aerosols into the atmosphere. Especially since the costs and benefits wouldn't be shared equally across the globe. And alongside all of these issues, stratospheric aerosol injections could be used as an excuse to continue burning fossil fuels and increasing emissions. Which might be part of the reason why Silicon Valley thought leaders and billionaires alike find such an appeal in these silver bullet solutions. “The path to success is going to require innovation across every one of these sectors. In my experience innovation can do magical things.” Bill Gates is right. Innovation is important. But these innovations must be pursued in conjunction with the myriad of solutions already available. We must seriously tackle emissions reductions before we try anything else. Because as climate blogger and physicist Joe Romm notes, some of these silver bullet solutions are akin to using “a dangerous course of chemotherapy and radiation to treat a condition curable through diet and exercise — or, in this case, emissions reduction.” But reducing emissions could necessitate a transformation away from a society that makes billionaires like Bill Gates rich. This then, might be the reason why we cling to silver bullets. The distant hope of an easy answer allows us to continue our present actions. That is especially the case for companies and capitalists who profit off of our current emissions catastrophe. When we bet on “miracle” solutions like sulfate aerosols, we choose the highly risky but seemingly straightforward to implement option over a low risk but transformative one. Emissions solutions like renewables can offer decentralized, clean energy for billions of people around the globe, while free, electrified transportation infrastructure can pull millions of gas guzzling cars off our roads. Yes, these answers might have to fight an uphill political battle to be implemented, but they exist here and now and bring a whole lot more equity and democracy to the table compared to pouring sulfur gases into the stratosphere. If we do indeed need BECCS to stay under 2 or 1.5 degrees, it can't be the full picture - only one single piece of the bigger puzzle. The answer to mitigating climate change will never be found in one miracle technology, we have to use the multitude of answers currently in front of us, from electrified trains to decentralized solar to the redistribution of food waste if we want to mitigate climate change quickly. We can't wait around for new tools to mature to start dealing with climate change, we need to begin drastic economic and social transitions now to create a zero carbon future. A future that is environmentally ethical and just where we don't have to dim the sun in order to live. In order to collectively create and build this fossil fuel free world we'll need scientists, mathematicians, and engineers--problem solvers who know the consequences of a world with climate change and are invested in preventing it. Luckily, Brilliant is already teaching this next generation of problem solvers through an amazing selection of online courses that use interactive puzzles to hone critical, mathematical, and scientific thinking skills. And the best part is, you can learn these skills from the comfort of your own home. Brilliant is a course-based website and app that lets you explore the realms of math and science through storytelling, interactive explorations, and daily challenges. Which is exactly what you'll get when you dive into their Calculus in a Nutshell course. Using visual and physical intuition to present the major pillars of calculus, Brilliant guides you through the intricacies of calculus: an essential tool for aspiring ecologists and urban planners alike. Ultimately, if you're like me and are curious about how the world works or just want to build your problem-solving skills, then I'd highly recommend getting Brilliant Premium to learn something new every day. So, if you want to start developing your analytical abilities, go to brilliant dot org slash OCC, or click the link in the description, and sign up for free. As a bonus, the first 200 people that go to that link will get 20% off their annual premium membership. Hey everyone, Charlie here. If you haven't already, I'd highly recommend heading over to Climate Adam's channel and hit the subscribe button and then watching the video we made together all about Nuclear Fusion. Adam's channel is awesome, and brings some much needed levity to the climate change conversation. Hope you're doing well and I'll see you in two weeks!