Allowing 1.5°C warming will mean more extreme weather: Jean-Pascal van Ypersele

Jean-Pascal van Ypersele, former vice chair of the Intergovernmental Panel on Climate Change, said “Laying too much stress on geoengineering to modulate global warming can put the planet on a higher risk trajectory”

Allowing the world to get warmer by more than 1.5°C over pre-industrial times would mean significantly more heatwaves, extreme rainfall and droughts than if it stayed below that threshold. Most of these impacts will leave an irreversible imprint on ecologies and people, said Jean-Pascal van Ypersele, former vice chair of the Intergovernmental Panel on Climate Change, the world’s largest collective of climate experts. Laying too much stress on geoengineering to modulate global warming can put the planet on a higher risk trajectory, he said in an email interview ahead of the release of an IPCC synthesis report on Monday. Ypersele is a Belgian climatologist attending the IPCC meeting at Interlaken in Switzerland, which is running overtime. Edited excerpts:

HT Image

Do you think the 1.5°C goal is still realistic to pursue?

First, one should remember why this number has been chosen as the most ambitious goal of the Paris agreement: because the amount of human suffering, particularly, but not only, in tropical and developing countries would be much larger if the average global warming allowed was above that number. This was clearly demonstrated by the IPCC special report on 1.5°C warming published in 2018. Second, if that goal was chosen to avoid certain impacts, it is not because it is difficult to achieve that it should be abandoned. The latest IPCC report, published last April, has shown the window of opportunity was closing fast to stay below 1.5°C warming, but it was still possible to achieve it. However, this requires much stronger ambition and political will, particularly from the countries with the highest emitters per capita.

What are the consequences of an overshoot?

Leaving the world warming by more than 1.5°C on average would mean significantly more heatwaves, extreme precipitation, droughts, and ice melting than if we stayed below that threshold. The long-term consequences for sea level would be severe as well, particularly as the large ice masses of Greenland and Antarctica would add many metres to sea level over the next thousand years, threatening the lives of many coastal communities and even whole island states.

How do you think IPCC can play a role in keeping the Paris Agreement goals alive?

The IPCC must first explain and repeat why we need to act much more than we have done up to now. For so many people, it is a question of survival. Second, it must highlight the many options available to adapt to the part of climate change which is there already, in order to reduce human suffering and ecosystem damage as much as possible. Third, it must explain how those options can be implemented while reducing emissions to avoid the part of climate change that can still be avoided, while achieving as many sustainable development goals as possible (eliminating poverty, fighting hunger, ensuring energy and education access to all, achieving gender equality). The IPCC must be a beacon of quality scientific, technical and socioeconomic information, available in clear and understandable language to all the governments and economic actors. This will help them to act effectively on one of the most pressing challenges facing humanity.

What are your views on geo-engineering?

Let us not try to hide the huge risks associated to climate change behind a solar mask susceptible to create even more risks. As the IPCC has shown repeatedly, solar radiation modification (SRM) would not solve the problem at its root, which is the increase in CO2 and other greenhouse gas concentrations, and could even create new problems. The effects on the hugely important monsoon are not well known. Those on the ozone layer protecting us from excess UV radiation could also be severe. SRM would need to be applied at increasing doses if the root cause of the warming is not addressed. Meanwhile, ocean acidification due to CO2 emissions would not be ameliorated at all by SRM. Thinking about SRM as a solution distracts the world from the real solutions at hand: adaptation and mitigation, which both need more ambition and better means of implementation.

Do you think we will be able to bend the emissions curve?

I know because that is what the IPCC has concluded after assessing thousands of scientific articles, that bending of the emissions curve is as possible as curbing the Covid mortality curve has been possible. Like for Covid, what is needed are political will, ambition and a much stronger spirit of international cooperation and sharing.

What do you think of India’s strategies to deal with climate change, particularly the lifestyle for environment movement?

It is not the role of IPCC to comment on individual country’s policies and measures, but I can say that the emphasis India is putting on sustainable and environment- friendly lifestyles very much echoes the latest IPCC WG3 report observation that emission reductions of 40% to 70% were possible in several sectors in 2030 compared to the business as usual trajectories by acting on demand and behaviour alone, which includes lifestyle. The efforts India makes in the area of renewable energy are also important steps in the direction of decarbonisation and climate protection.

You will contest elections for IPCC chair’s position. What is your vision for the organisation?

If I am elected IPCC chair, I will make it the most scientific and strongest possible voice of climate in the international arena, lead the IPCC to new heights by making it the most dynamic, relevant and useful for policymakers. I would also work hard to make the IPCC the most inclusive ever. Gender balance, developing country participation, young scientists’ participation and respect and collegiality throughout the organisation will be key aspects of my chairmanship.