‘1.5°C global warming limit not realistic but that’s no reason to despair,’ says top climate scientist

Dr Friederike Otto, one of the authors of IPCC report on climate change, talks about the 'political sense of urgency' required to limit global warming to 1.5 degrees Celsius.

Dr Friederike Otto, senior lecturer at the Grantham Institute for Climate Change and the Environment, Imperial College London | Photo: By special arrangement

New Delhi: The Intergovernmental Panel on Climate Change (IPCC) released its final report as part of its Sixth Assessment Cycle Monday, stating that global warming is likely to cross 1.5 degrees Celsius above pre-industrial levels by as soon as the next decade unless drastic changes are made now.

Limiting global warming to 1.5 degrees Celsius by the end of the century is considered a global benchmark of climate action set by the Paris Agreement.

The effects of climate change will magnify with every increment in global warming, the latest report confirmed, calling for rapid and immediate reductions in greenhouse gas emissions. Current emissions scenarios suggest the world is on its way to crossing 2 degrees Celsius of warming, the report said.

Called the ‘Synthesis Report’, it is the last to emerge from the IPCC for the next seven years and brings together the findings of the three working groups that were released between 2021 and 2022. The report highlights the need for equitable climate action and calls on developed countries to mobilise the finance needed to transition away from fossil fuels.

ThePrint spoke to Dr Friederike Otto, one of the authors of the IPCC report and senior lecturer at the Grantham Institute for Climate Change and the Environment, Imperial College London, about some of the key points from the Synthesis Report. Edited excerpts:

Is there undue optimism around limiting global warming to 1.5 degrees Celsius, given that science says we are very likely to cross it within the next decade?

I think we need to be optimistic because we are already at 1.1 degrees, and we have now seen the gravity of the impact climate change can have on lives and livelihoods. We cannot just despair and do nothing. We need to work to (limit global warming to) 1.5 degrees, but of course, we also need to make this goal realistic. At the moment, the 1.5 degrees goal is not realistic.

While we do have all the knowledge and the tools and technology that we need, we do not have the political sense of urgency, the political government frameworks and policies that are needed to achieve it. So, we need to make (the goal) realistic, but it won’t be if we keep doing politics and economics as we are doing right now.

The World Meteorological Organization says it’s very likely we will breach the 1.5 degrees threshold temporarily between now and 2026. What impact is South Asia likely to see on account of this?

It is important to differentiate between reaching 1.5 degrees in a single year — and that can happen as soon as next year — and reaching 1.5 degrees over a number of years, as (is happening) with the global mean average temperature. Crossing 1.5 degrees is something we are likely to see in the early 2030s.

Reaching and breaching 1.5 degrees will have severe consequences for humans and ecosystems, particularly in South Asia. Last year, India and Pakistan saw a dramatic heatwave with huge impact on people, agriculture and the economy. And it’s already very hot again, even though it’s just early March. Even February was very hot in India.

If we overshoot 1.5 degrees, then the pre-monsoon seasons we see now will feel cool in comparison to what we will be seeing then. So, there’s a huge amount to be gained to not overshoot 1.5 degrees. It is definitely important to fight for it and implement all the knowledge we have now.

Three million years ago, global mean surface temperatures were much higher than what we’re experiencing today. Why is today’s global warming more worrying?

Three million years ago it took many thousands of years for temperatures to reach those levels and therefore ecosystems had time to adapt. That is totally different to what we see today. Today we have seen these temperature increases in such a short timespan that no ecosystem and no human system has had the chance to adapt. That’s something this report shows very starkly, which is just how vulnerable we are to these rapid changes in global temperature.

The summary for policymakers (SPM) says fossil fuel use must be “substantially” reduced, but stops short of calling for a phase down or a phase out. Why is this, and what does the science indicate?

It states very clearly that if we want to achieve the 1.5 degrees goal, we need to reduce global carbon dioxide emissions to net zero by 2050 and reach net zero greenhouse gas emissions later this century. We can only achieve this if we stop burning coal, oil and gas wherever possible.

So, it is absolutely impossible to achieve these goals by further investing in or subsidising (fossil fuels) as it’s currently done. But of course, the IPCC report is a scientific document. So, it shows what needs to be done from a scientific point of view. It is the policymakers who need to draw conclusions from a policy point of view and implement them.

The SPM says carbon dioxide removal (CDR) is necessary to achieve net negative emissions. To what extent do you view this as a solution given that there is no proven, large-scale technology at the moment?

I think we might need CDR for the very hard to abate emissions, such as from agriculture and aviation. But it’s not a solution on a large scale, because we do not have the technology and we need to act now.

We do have all the other technologies that we need to replace current fossil fuel emissions on a very large scale. So, focusing on CDR is the worst thing we could do because it would mean kicking the can further down the road and then (limiting to) 1.5 degrees will definitely be out of reach.

All traffic on land can easily be done now with today’s technologies, without burning fossil fuels. Heating, energy generation — all of it we know how to do without burning fossil fuels. That is what we need to focus on implementing now.

Scientists from the global south have critiqued the IPCC’s development projections, and argue that they perpetuate carbon inequities and place the burden of climate mitigation on developing countries. The SPM includes a box that somewhat acknowledges this. What motivated this inclusion, and what should policymakers make of this?

The problem that we are in with climate change is a problem that is generated from huge global inequity. The people and the countries who caused the problems are not the ones suffering the most, and not the ones who are most vulnerable, and not the ones who are paying the price.

It is impossible to achieve any of the sustainable development goals without doing mitigation and adaptation through an equity lens. We will not be able to make our societies less vulnerable. It’s absolutely crucial to see everything through an equity and justice lens. The IPCC has started with this box to try and do that but there’s still a long way to go at the moment. A lot of the research is driven by the global north without using that equity lens, and that has to change.

It’s important to make sure these inequities are not perpetuated into the future. Even if fossil fuels were to be replaced by EVs, for example, it should not be the case that the global south is paying for that transition for the global north by providing mining materials etc.

What do you think a country like India has to look forward to in this report?

I think a country like India should try, wherever they can, to make sure that its global finance goes towards sustainable mitigation and adaptation processes. That is one of the big barriers to sustainable mitigation and adaptation at the moment. It’s not that there’s not enough money in the world, but it is that the money goes to the wrong places — it’s not going towards financing adaptation and truly sustainable mitigation. That, I think, is something that is really important for a country like India.

(Edited by Zinnia Ray Chaudhuri)