I’m on the train home to Lund, Sweden, returning from last week’s gathering of 2,000 climate change scientists from 100 countries at the Our Common Future Under Climate Change conference in Paris. The meeting was the largest gathering of scientists in advance of the United Nations talks that will also take place in Paris starting November 30th, where the next round of an international climate deal will be negotiated.
The meeting summarized the state of the science, and looked ahead for the role science could play in the months leading to Paris, and beyond. I’m using this time speeding past German wheat fields and over sparkling Danish lakes to reflect on my impressions of the conference.
My summary of the key messages: the risks of unchecked climate change are increasingly scary, prompting scientists to turn towards a focus on preparing for the inevitable risks while calling for fundamental changes to our energy systems to avoid the worst impacts.
I see it as a time of reckoning for the scientific community: this pivot towards focusing on solutions recognizes the increasingly unavoidable ethical dimensions of studying such a huge threat.
Are you a UNFCCC negotiator or IPCC author? Skip this section. Otherwise, here's the deal:
In 2009, 141 nations agreed in principle to limit climate warming to 2°C (3.8°F) above pre-industrial temperatures, in line with an international agreement made in 1992 to avoid “dangerous anthropogenic [human-caused] interference” with the climate system that could threaten food production and ecosystems. The 2° target has been criticized, but it’s clear that the risks of climate change increase with greater temperatures. (Read more on climate diplomacy here from Brad Plumer at vox.com.)
We have already used up almost half (0.8°C) of this 2° allocation, and at current emission rates, we are on pace to warm up to nearly 5°C (9°F) by the end of the century.
Five degrees may not sound like much, but when the Earth was last 5°C colder (about 20,000 years ago, due to natural variations in its orbit around the sun), Chicago would have been buried beneath an ice sheet more than twice as tall as the Sears Tower. For nature, for cities, and for people: five degrees is a huge difference, and a five degree warmer world would be largely unrecognizable to us. Thus the focus on bending the path we’re on to limit the amount of future warming that occurs, while also aiming to meet other goals like eliminating poverty.
It’s warming, it’s us, we’re sure… now what?
Although the notion that the Earth is warming and this warming is caused by human activities sometimes still appears to be contested in the media, after decades of accumulation of overwhelming evidence and analysis, there is really no scientific debate about this.
Therefore the discussion at this scientific conference focused on two areas: the “problem space” of the risks posed by continued climate change, and the “solution space” of opportunities to address and lessen these risks.
News flash: Climate change is bad
Even for an audience who works with climate change data every day, there were some stark reminders of how serious the problem is. Over the past years, as evidence accumulates, scientists have progressively revised their estimates of how likely dangerous risks like extreme weather events or major ice sheet collapse are. I attended one session that traced this history, showing that, in the latest report, a new color scheme had to be introduced to capture “very high” risk of some of these serious reasons for concern under warming of more than 2°C. That means- the risks of climate change are worse than we thought.
It’s not just future projections – the effects of climate change can already be seen today. Camille Parmesan of Plymouth University showed that across continents and ecosystems, half the species studied have already changed where they live, and two-thirds changed when they live (for example, flowers blooming earlier in a warmer spring) to track changing climate. This large response to the relatively small changes in temperature we’ve seen today is worrying for the future.
Paul Leadley of the Université de Paris-Sud argued that our common future should recognize the value of the many species with whom we shared the planet, whose options under climate change are limited to “move, adapt, or die.”
Clearly, the path we are on is a bad one. It’s no surprise, then, that much of the meeting focused on what we should do about changing it.
Manage changes we can’t avoid, and avoid changes we can’t manage
Historically, the relationship between limiting climate change (mitigation) and dealing with its impacts (adaptation) has been a contentious one, with concerns that a focus on dealing with the effects of warming could decrease motivation to limit the warming that occurs. (This is a bit like a patient who thinks he can keep up a sedentary lifestyle fueled by unhealthy foods as long as he takes blood pressure medication, rather than making lifestyle changes to eat better and exercise more to prevent high blood pressure in the first place.)
However, a more unified voice emerged from this conference, noting both the need for strengthening our capacity to adapt to climate change, and the limits that we face in managing risks under increasing warming.
In daringly PowerPoint-free reflections, Saleemul Huq of the International Center for Climate Change and Development noted that adaptation is not just dealing with risks, but taking opportunities to be better off and to make transformational changes. He cited the example of sending kids from areas facing saltwater intrusion in his native Bangladesh to school to give them opportunities other than farming. However, he also cautioned that some people face big risks under even the low range of warming, and it’s very doubtful that adaptation can be a sufficient solution in a +3 or +4°C world, sharpening the need for mitigation.
“The age of carbon is over”
The ultimate conclusion of the conference, summarized by Scientific Committee Chair Chris Field at the closing plenary, was that “We are moving to a post-carbon era, where climate change mitigation and adaptation are combined with other goals to build a sustainable future.”
Why a “post-carbon” era? Recent analyses have concluded that we have a limited amount of carbon we can release to the atmosphere in order to hold warming to 2°C or less (the so-called carbon budget). If we emit more than this, we risk experiencing higher warming, where risks become more severe and less manageable.
Previous research has shown that, to meet a 2° target, the majority of fossil fuel reserves including 80% of coal and half of gas reserves should remain unused. At the conference, Chris Field noted, “We’ve never said, let’s cut down the very last tree, let’s catch the last fish in the ocean. Why should we burn the very last carbon?”
The conference Outcome Statement reaffirmed that our carbon budget, the amount we can emit from here to eternity, is only about 20 years’ worth of current emissions. Further, because of the long lifetime of greenhouse gas warming pollution in the atmosphere, to achieve a stable climate, carbon emissions must eventually go to zero. (This means "decarbonizing"- using clean energy to get the services we want, like hot showers and cold beers, without the carbon pollution to the atmosphere that inevitably accompanies burning fossil fuels to deliver them.)
Hans Joachim Schellnhuber of the Potsdam Institute for Climate Impact Research expressed this same view more bluntly: he sounded a clarion call that “the age of carbon is over.” He warned that "it is a very bad idea to go beyond two degrees” and suggested: “Let's take this as the reference line, what are we going to do about it?” He said that if there is any chance of avoiding dangerous climate change, an "induced implosion of the carbon economy” is needed.
Society’s response to climate change
Indeed, there was converging agreement from scientists, political leaders, and journalists at the conference that fundamental changes are needed to achieve a zero-carbon society, not just incremental improvements at the margins. Several high-level French politicians and diplomats at the meeting were blunt about the urgency of tackling climate change. French Research and Education Minister Najat Vallaud-Belkacem issued a stark warning, saying that "unless we have widespread climate action, we will be the generation that knew what had to be done, but didn't do it." Segolène Royal, French Minister for the Environment, Energy and Sustainable Development, echoed the same message, calling on scientists to speak with a clear voice in the run-up to the Paris climate change negotiations in December. "We have won the battle of ideas, now we must win the battle for action," she said.
The conference featured a packed lunchtime session on one approach for changing course that’s rapidly gaining traction: the fossil fuel divestment campaign. Scientists came to hear Damian Carrington, Head of Environment at The Guardian newspaper, describe the paper’s #keepitintheground campaign, which he said was "rooted in the reality that there’s far more carbon locked in the ground than we can safely burn.”
Several speakers including Karen O’Brien emphasized that if we act swiftly and boldly we have the technical capacity to meet the 2° target. Nobel laureate Joseph Stieglitz pointed out that this action could present economic opportunities. A key question now seems to be: how do we get there?
Pivoting from problems to solutions
Many scientists seem to have decided to dedicate themselves to answering this question. This is part of a larger shift in the scientific community that I saw throughout the conference, articulated by Chris Field in the closing plenary as a “pivot” from problems to solutions. He described the scientific community shifting its focus from describing the climate change problem, to exploring and evaluating solutions to decrease the amount of warming that occurs, and prepare for the warming that cannot be avoided.
As part of envisioning and exploring solutions, as well as motivating action, several speakers talked about the need for scientists to help create a positive vision of a better future. In particular, Ken Caldeira of the Carnegie Institution for Science raised the need to highlight the attractive elements of a low-carbon future, to imagine the world we’d like to create: full of healthy, happy, prosperous people. Jeffrey Hardy, an energy regulator from the UK, echoed this need, pointing out that there could be something for everyone in a low-carbon future, whether it was smart technology or better communities or clean air for everyone. Even without considering the added benefits of addressing climate change, he concluded: “Don’t we want to live there anyway?”
There was a bright spot for hope that social and political change can be possible, and sometimes more rapid than scientists predict. A story shared by Diana Ürge-Vorsatz offered a potential lesson for the climate negotiations this fall, where ambitious goals spurred change much faster than expected: “When we wrote about zero-energy buildings less than a decade ago, most researchers didn’t think it was possible. Today it’s in European law. The law came out before the scientific community was convinced it was feasible. The regulations pushed the industry to innovate, and it’s having a very significant impact. Really, a miracle happened.”
The human challenge of climate change
Finally, I saw a welcome expansion at the conference beyond a focus on technical challenges of climate change to address underlying ethics. I see this as a sign that scientists are examining their role in society more closely, and trying to find ways to make their contribution meaningful. For example, Karen O’Brien pointed out that addressing climate change forces us to ask what risks we can accept or tolerate, which is a question of beliefs and values.
Chris Field outlined a new role for science in bringing objective analyses to the table to inform ethical debates. He emphasized the human questions raised by climate change, forcing us to articulate and perhaps change “how we think about the interests of the poor versus the rich, the future versus the present, and nature versus economies.” This kind of thinking is a fundamental transformation indeed, one that will carry on well beyond the next few months on the road to Paris.
Studying climate change offers us the chance both to push the frontiers of scientific knowledge, and to delve deeply into human nature. As a researcher, I have studied the impacts of climate change on crop yields and quality. My findings, along with the mass of evidence accumulated by hundreds of my colleagues, worry me that we are eroding our ability to feed ourselves- one clear reason in my mind to urgently reduce climate change. But it’s clear that research findings alone are not sufficient to change policies and agreements- much less hearts and minds.
Faced with the stark realities of climate risks, as well as cautious optimism that change is possible, I left the meeting wondering how the response to climate change will unfold this fall and beyond. I will be back in Paris in December to watch one pivotal moment where the nations of the world will express their values, in ways that will be seen and felt for decades to come. When I think about Our Common Future, it is my hope that it is one that will reflect the best of human nature.
This post draws on daily newsletter updates that Johannes Mengel of the International Council for Science and I wrote during the Our Common Future Under Climate Change conference, and benefitted from his helpful editing. The original newsletters can be read here: Day 1, Day 2, Day 3, Day 4, and the Wrap-Up.