Editor’s note: This commentary is by Isaac Bissell, of South Burlington, who is a member of Extinction Rebellion.
When I listen to discussions about climate change these days, I am usually left with one consistent thought: The urgency behind the issue is not being understood. I hear people talking about food waste, solar panels on homes, electric cars, and other solutions that are within easy reach. Often the discussion centers around how individuals can change their behavior in order to reduce their individual carbon footprint. These are all well intentioned thoughts, but they fall desperately short of what is required. To look at what is truly required, we should first examine the Intergovernmental Panel on Climate Change report that came out last fall.
The report outlined the steps we must take in order to limit warming to 1.5 degrees C, and explained the potential impacts of exceeding this level of warming. It stated that limiting warming to 1.5 degrees Celsius “would require rapid, far-reaching and unprecedented changes in all aspects of society.” The summary for policymakers highlighted the need for urgent action by comparing the difference between 1.5 degrees C and 2 degrees C of warming above pre-industrial levels. The difference in impacts are, of course, incredible and alarming. This said, what is often missed when reporting on this difference is that with every bit of warming over 1.5 degrees C, we increase the risk that we will set climate feedbacks into motion which will drive additional warming. This is because the IPCC uses a consensus based approach in writing their reports, and therefore our latest understanding of the science is often omitted from the report. In this case, the omission of the consequences of climate feedbacks from the IPCC report has serious implications. So, what are climate feedbacks?
There are two types of climate feedbacks, positive feedbacks and negative feedbacks. A negative feedback is a process that decreases the severity of some initial change, and a positive feedback increases the severity of the initial change. Unfortunately, when it comes to the addition of greenhouse gases to the atmosphere, most of the feedbacks we have seen to date are positive. An example of a positive feedback is the melting of the sea ice in the Arctic Ocean. Over the last several decades, the extent of sea ice in the Arctic Ocean has been falling due to human induced warming. This means less ice and more open water. As sea ice is white, it reflects the sun (and the sun’s warmth) back into outer space. However, when that ice melts and the sun hits the dark colored ocean, the light (and the sun’s warmth) is absorbed by the ocean. This warms the ocean, which has a warming effect on our climate, and also accelerates the melting of the ice (which then creates more warming). There are many other positive feedbacks that have already been set into motion, and some which will soon be set into motion if the climate continues to warm. A recent paper, commonly referred to as the “hothouse earth paper,” analyzed 10 positive climate feedbacks came to the following conclusion:
“Human emissions of greenhouse gas are not the sole determinant of temperature on earth. Our study suggests that human-induced global warming of 2°C may trigger other Earth system processes, often called ‘feedbacks’, that can drive further warming – even if we stop emitting greenhouse gases. We show how industrial-age greenhouse gas emissions force our climate, and ultimately the Earth system, out of balance. In particular, we address tipping elements in the planetary machinery that might, once a certain stress level has been passed, one by one change fundamentally, rapidly, and perhaps irreversibly. This cascade of events may tip the entire Earth system into a new mode of operation. These tipping elements can potentially act like a row of dominoes. Once one is pushed over, it pushes Earth towards another. It may be very difficult or impossible to stop the whole row of dominoes from tumbling over. Places on earth will become uninhabitable if ‘hothouse earth’ becomes the reality. What we do not know yet is whether the climate system can be safely ‘parked’ near 2°C above preindustrial levels, as the Paris Agreement envisages. Or if it will, once pushed so far, slip down the slope towards a hothouse planet. Research must assess this risk as soon as possible.”
A key term in the above quote is “tipping element.” More often, one hears of tipping points, which are defined as “a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system”. The nature of tipping points is that it is difficult to know where they exist in a system until they have been crossed and the system is in a new state. The Arctic is one ecosystem that appears to be nearing a tipping point, if it hasn’t already been crossed. The steady decline in Arctic sea ice extent, if it continues, will lead to an Arctic Ocean that is one day entirely free of sea ice. After a certain point, due to the warming of the Arctic Ocean from lack of ice, we will have crossed a threshold, and no amount of emission reductions will prevent us from moving to an ice free Arctic. The point after which we cannot prevent the Arctic from moving to an ice free state is called the tipping point. A tipping element from the perspective of the earth’s climate system is a component of the system that has the potential to cross a tipping point and enter a new state. The concern expressed in the hothouse earth paper is that there is a potential for one tipping element (e.g. the Arctic ecosystem) to interact with other tipping elements resulting in domino like effect where tipping points of multiple components of the climate system are crossed. While the paper stated that it is unclear how much we can warm the planet before we trigger this type of chain reaction, the authors recommended that we keep warming as far below 2 degrees C as possible to reduce the risk of this occurring.
The reason melting sea ice in the Arctic is so often used as an example of a climate feedback is because it is this particular feedback that has driven many of the changes in our climate system to date, and it is likely to be a major driver of change going forward. As the amount of greenhouse gases in our atmosphere rises, for a number of reasons, the Arctic warms more quickly than the lower latitudes. One of the primary reasons for this accelerated warming is the previously described sea ice melt dynamics. Unfortunately, this accelerated warming of the Arctic has meant that another positive feedback has been set into motion.
The Arctic has approximately 9 million square miles of permafrost (the size of the U.S. and Canada combined). Permafrost is ground that has been frozen for at least two years, although most of it is much older, and some is hundreds of thousands of years old. This frozen ground holds incredibly large reservoirs of carbon, and because the Arctic has been warming so quickly, the permafrost has begun to melt at alarming rates. When the permafrost melts, the organisms in the soil that have been inactive due to their being frozen begin to wake up. As they wake up they begin to consume the organic matter in the soil, and this releases greenhouse gases such as carbon dioxide and methane. The melting of the permafrost in the Arctic has the potential to be an enormous positive climate feedback, but scientists have expressed uncertainty as to how quickly the melting will progress. This meant that the permafrost feedback dynamics were by and large ignored by the IPCC in their report. Unfortunately, this June we had reports from scientists in Canada that permafrost that is over 1,000 years old is now melting 70 years faster than scientists had predicted. This is a chilling sign, to say the least.
Unfortunately, the permafrost situation isn’t the end of the story when it comes to the effects of a warming Arctic. The warming Arctic has also meant that there have been changes to the jet stream, which is now loopier and has the tendency to get stuck into place. It is this tendency to get stuck in a loopy pattern that caused the flooding in the Midwest this spring and the terrible heat waves in Europe this summer. The acceleration of changes that we have begun seeing has caused scientists around the globe to begin raising the alarm about the potential for these feedbacks to trigger the chain reaction described in the hothouse earth paper. The truth is, at the moment, we do not know where the planetary tipping point described in the hothouse earth paper might be or if we have already crossed it. Scientists still believe that we have time to avert the most catastrophic effects of climate change, but each year we continue to ignore their warnings our situation becomes more desperate. In 2018 we put our foot on the gas, setting a global record for greenhouse gas emissions. We may still have time to act, but we do not have time to mess around.
In the event this is new information, I am very sorry to be the bearer of such terrible news. People are often looking for hope after reading the latest bad news about climate change. In my opinion, this desperate need for hope, which is entirely understandable, often leads people to underestimate the threat of climate change and to propose solutions which are viable in terms of our ability to accomplish them, but fall wildly short of what is necessary. Hope of this sort is not hope at all, it is delusion. True hope, in my mind, comes not from an overly optimistic outlook, but from an accurate assessment of the situation followed by a response which will actually address the threat that we are facing.
What has given me hope is actively working with a group that shares a vision as far as a path to systemic change. The group that resonates with me most is Extinction Rebellion, but there are so many other wonderful groups in Vermont and around the world that are working to fight for the systemic change that we so desperately need. In Vermont, these groups have banded together to form a coalition that has been working together to support the youth led global climate strike from Sept. 20-27. The week will kick off with the global climate strike on Sept. 20, when adults are invited to walk out of work in support of the youth climate strikers who will be walking out of school. Actions and events will continue worldwide all week, and the Vermont coalition of climate organizations has set up a website (wwww.vermontclimatestrike.org) where you can view a schedule of events and reach out to the organizers if you would like to get involved.
True hope springs from the potential that is brought into our awareness when we band together. Humans are very capable, and in times of crisis we can accomplish incredible things with the single-minded focus that an emergency provides. While we have not been living up to our potential, in confronting this crisis we have the opportunity to move in a different direction. I invite you to join us, if your circumstances allow, by planning to walk out of work on Friday, Sept. 20, and in joining us at the other events throughout the week.
