The never-ending cycle

Professor Le Quéré, you are a physicist and oceanographer and have been recognized many times for your contributions to climate change research. Your work includes co-authoring three assessment reports of the International Panel on Climate Change, and leading the annual Global Climate Budget update of the Global Carbon Project for 13 years. What exactly is the Global Carbon Project?
Scientists worldwide collect data on the level of emissions, where CO2 originates, and how it is distributed in the environment. This update is then made available to political decision makers for climate agreements. We know that about half of emissions stay in the atmosphere and the other half are absorbed by natural reservoirs, called carbon sinks, which include the oceans, plants, and the terrestrial biosphere. So, there is a certain budget for the amount of carbon that can be absorbed.

Humans influence the carbon cycle. You have said that, in many regards, the reality looks a lot scarier than the examples on paper. What do you mean by this?
Scientists have been warning us for decades. Either you believed them or you didn't. Today, anyone who is about 30 or older, can see the changes with their own eyes: heat waves and the resulting risk of extreme forest fires and increased mortality rates. In 2003, we saw the extreme heat wave in Europe, during which tens of thousands died. Again, this summer there were 1500 additional deaths due to heat. And this I find scary. Likewise, global warming gives cause to extreme events such as heavy rainfall. The rising sea level not only causes flooding, it also intensifies the effect of storms, hurricanes, and heavy rainfall. It is difficult to remain passive in the face of such threatening and powerful Events.

Why do you think people, and especially politicians, didn’t listen during the past decades?
There is progress. Policymakers did sign the Paris Agreement in 2015, a major pillar in international action. It is important to highlight, that while, yes, emissions continue to rise globally, there are actions ongoing in the background. It’s not simple. Many countries who signed haven’t really realized what this means. Some are taking the goal of “net-zero emissions by 2050” more seriously and are strengthening their efforts to meet the target agreements. And in Europe especially, particularly France, Great Britain and Germany, it is also being discussed. However, there hasn’t been sufficient incentive to make this a priority.

Is this due to a lack of technology or a lack of will in industry?
It’s more than a question of will. We need to change the way we consider the environment in our decision-making. This applies to politics, business, and individuals. For example, budgets need to be aligned with the objectives of climate change. When we take decisions about building infrastructure or making new laws for transport, they should have weight associated with their impact on emissions. The costs for environmental pollution are much too low to really influence decisions. There is a lot of discourse but insufficient reflection at the policy level. 

Human activities have set in motion a train of changes in the natural carbon cycle. Can you briefly tell us about this?
We have to maintain the absorption capacity of the natural sinks and consider that all of our actions influence their health and thus our budget. Forest fires caused by heat waves destroy trees, a natural CO2 sink. The warming of the oceans, for example, both emits more CO2 from the water while also causing the ocean to lose its capacity to absorb CO2 – this has an accelerating effect. The higher the emissions, the weaker the effects of the sinks.

The carbon sinks are curbing climate change but are beginning to reach their limits. You propose a mandatory planetary monitoring system which would observe the rapidly changing carbon cycle. How would this work?
This idea originated from the Paris Agreement. The signatories agreed to verify observations, so that they have a solid foundation of findings. The scientific community is trying to develop ways to verify emissions without observation. This includes observing biomass and the use of certain chemicals, or implementing satellite observation. At the moment, each country is collecting their own data and they have to trust each other. There is no independent verification. We currently do not yet have any data. We can only confirm that the emissions reported are okay. This will be the task in the immediate future.

The interaction between science and the public is changing. What do you think of the influence of the latest movements such as Fridays for Future?
I think the interactions between scientists and policymakers are changing. In the past 25 years, the flow of information has changed. Scientists were leading the scientific agenda and providing policymakers with evidence. Now questions are coming from outside more often. Society and policymakers have a lot of questions back to scientists. We control the research agenda less but our research is becoming more useful. Scientists are being asked to provide support for many decisions that are not necessarily in our core specialty but that take our general know-how into consideration. As a trained oceanographer, I'm a specialist in carbon sinks, but I am asked to sit on many committees addressing a wider range of topics. One example is estimating the carbon footprint of large events like the Olympic Games. As a scientist, I get asked to sit in circles where decisions are made, not to make decisions myself, but to ensure that processes respect the science.

What can be done to push international leaders towards a common course of action and what should individuals do to choose a livable future?
I think that international leadership has to go through the Paris Agreement as the main framework but there are also other frameworks such as the G7 or G20 summits. There are also multilateral coalitions which are very useful to apply pressure from all sides. These coalitions ensure you are not alone in your actions.
There are a lot of things individuals can do: For example, we can think about the mode of transportation we use, how we heat our homes, and our nutrition – where our food comes from and the carbon footprint resulting from production and transport to get it to our plates.
One has to recognize that individuals can do things but the priority has to be for government action. Without this, the scale is simply not there. I’d like to add that my presentation is not going to be all gloom and doom. I want to motivate people. I hope attendees leave thinking “Oh I know what to do next.” There is a role for everyone to play, and policymakers are continuing to show more readiness. They must be supported to continue to do the right thing, and to do it quickly.

Interviewer: Patricia Pätzold

Global Carbon Budget 2019:
www.earth-syst-sci-data-discuss.net/essd-2019-183 [2]