Year on year, for several years, we have been experiencing the hottest average temperatures on record. What are the latest key indicators telling us about the state of the climate system and human influence in the lead up to 2030?
2024 was the warmest year on record, both in global air temperature and in global sea surface temperature. It also marked the highest concentration of greenhouse gases in the atmosphere, and the sharp increase is due to human influence. We have known the cause of human-induced climate change for at least the last 40 years. The first IPCC reports came out in the early 1990s. We also know the solutions, as nations around the world committed to the Paris Agreement in 2015 to limit climate change to 1.5 degrees.
However, we ended 2024 as the first calendar year above 1.5 degrees. This is significant. While one individual year does not break the Paris Agreement, the warmer our global climate is, the more extreme events we experience – wildfires, floods, droughts, and heatwaves – leading to both human and nature suffering. With rising temperatures, we also see glaciers, ice sheets, and sea ice melting. The melting of ice on land leads to sea-level rise, which affects coastal communities and ecosystems. Humanity is making our society more vulnerable through our dependence on fossil fuels.
What is your response and that of the scientific community to these figures?
My response has evolved over time. We hear about records all the time, and I think there is a lot of record fatigue. As scientists, we deal with many statistics. It is my role and the role of my organization to monitor the climate and describe what is happening without sounding alarmist. It is a tricky balance – describing the records we are breaking and what they mean, while also reminding people that there is still hope. The reality is that our choices matter. We can choose to decarbonize and reach net-zero emissions as quickly as possible. The sooner we do that, the sooner the climate will stabilize.
In terms of the response from the scientific community, there has been a lot of shock and surprise at the number of records being broken. I vividly remember September 2023, when it was the warmest September on record by a truly shocking magnitude following a triple-dip La Niña, which normally has a cooling influence on our global climate. A climate scientist colleague described it as “gobsmackingly bananas,” and that has stuck with me for two years. There was some frustration, then, when reports came out saying scientists did not predict these temperatures, but that is not true. We are still within the range of what climate models predicted, but we are at the higher end of that range. For example, changes in shipping fuels, due to the IMO regulations in 2020, are influencing how much energy the ocean absorbs but it is difficult to quantify the impact on global temperatures and this is only one of several contributing factors. The science is still evolving, and we are still learning about the complexities of the climate system and how different components interact with each other. However, unless we reduce greenhouse gas emissions, the long-term upward trajectory will remain the same.
What is most interesting to you in the current climate science landscape?
For me, what is most interesting is the situation in the ocean. We know that the ocean has absorbed 90% of the excess heat from climate change, but it looks like the ocean is behaving differently in 2023/2024 compared to previous El Niño events, as ocean temperatures have remained very high, even after the peak of the El Niño event at the end of 2023.
We have scientific evidence that the global ocean conveyor is changing. Evidence suggests that the deep ocean around Antarctica has warmed over the last 30 years and is leading to a slowing down of the Antarctic circumpolar current in the coming decades. In the Northern Hemisphere, the important Atlantic Meridional Overturning Circulation (AMOC) has also slowed down due to a warmer, less-salty ocean and the potential collapse of the AMOC due to climate change is a critical tipping point. This is where the exciting science is: learning how the ocean’s behavior is changing, how the ocean and other parts of the Earth system interact, and what the long-term impacts of this warmer ocean could be.
When there is uncertainty about what is driving a phenomena or data expression, it can become baked into energy market and policy models. This is when scenario design becomes crucial. How do you negotiate those uncertainties when you are feeding your data into a scenario model with bodies like the IEA?
I find this a fascinating question. The short answer is, it depends. Our expertise lies in climate data and monitoring the climate system, but when it comes to understanding the implications for agriculture, energy security, and other sectors, we collaborate with experts in those fields who help downscale our data or make it more relevant to their needs.
It is never a one-size-fits-all approach, and the predictive models are never certain. We aim to describe where we have confidence in the data, and where uncertainty remains, so that others can draw their own conclusions.
Now we are talking about a 2 or even a 3 degree rise above pre-industrial levels this century. How high will global heating go?
For that, we would look to the IPCC reports. We use the same data from climate models that were used in the last IPCC report, and those data are available through our applications.
How much warming we will see depends on our actions, and while the climate is changing, the solutions are within reach. The transition is already happening – especially in Europe, where we have seen more renewable energy production and faster decarbonization than ever before. The co-benefits of decarbonizing are often overlooked. As we rely more on renewable energy, we gain energy security, reduce reliance on fossil fuel states with often unstable political regimes, and improve air quality. This leads to better public health and less pressure on health systems.
Can you share some examples of climate mitigation or adaptation measures that have been shaped by Copernicus' data?
The International Renewable Energy Agency (IRENA), based in Bonn, used our ERA-5 data to assess renewable energy potential across Africa. By analyzing wind and solar data, they identified the best locations for renewable energy in every African nation. This data has helped climate scientists negotiate with African countries to ensure that international aid is directed towards developing solar farms or wind energy projects instead of building new fossil fuel power plants. It is a great example of how having the data available enables quick and efficient decision-making.
Another example is the European Environment Agency’s Climate Adapt portal, which is built on Copernicus data. The portal allows cities and counties to analyze the historical changes in climate variables like heat stress and tropical nights. This has helped cities create climate adaptation plans. In the latest European report, we found that the number of cities with adaptation plans had almost doubled from 26% in 2018 to 51% in 2023. This shows that local authorities are quickly adapting to climate change and ensuring that communities can cope with its impacts, such as creating climate refuges, reforesting areas, and reducing the heat island effect.
Over the years, you must have answered the question “is this really caused by fossil fuels” hundreds of times. How have you seen climate change denial and acceptance change over the past decade, and how do you perceive it today?
It is interesting to see how the narrative has shifted. In the beginning of my career, the denial was that climate change was not happening or that humans could not possibly influence it. The scientific evidence for human-caused climate change has been clear for over 150 years, and we have known the impact of human activity on the climate since the 1930s. However, there will always be a small group of people who reject the evidence. I have seen climate scientists evolve in their approach, deciding not to engage with those people anymore. Now, the denial is focused on the solutions – claims that renewable energy is not secure enough, too expensive, or lacks certainty.
For me, science is not about belief; it is about evidence. If someone does not accept the evidence, that is not my problem. My challenge is to clearly present the scientific evidence and inspire people to take action. We can all make choices – whether at the individual, community, national, or international level – and even small actions can help move us in the right direction.
What is your message to government and business leaders gathering at COP30 and Climate Week 2025?
My message would be that the commitment was made a decade ago with the Paris Agreement, and we have just had our first year above 1.5°C. Looking at the data, although we have crossed 1.5°C in the short term, the long-term average is still around 1.35°C. Emissions projections suggest we will exceed the 1.5°C target by around 2030.
My message to politicians is simple: the commitment was made, and we have the technological solutions. These solutions are better for society and better value for money because they stimulate new industries and create new skills. We have to adapt to the new climate, and I believe that the only regret we will have is not acting more quickly.
