The Physical Science Basis report is the first instalment of the IPCC’s Sixth Assessment Report (AR6), which will be completed in 2022
Climate change has already begun and there is no going back. The Intergovernmental Panel on Climate Change (IPCC) confirmed the world’s worst fears in a report released today. The report, which has been backed by 195 governments, placed the blame squarely on human activities. India, the report stated, is expected to see a rise in the frequency and severity of hot extreme events and rain during the monsoon season.
The report does not envision a pathway that can limit warming to 1.5°C without crossing the threshold first. Which means warming beyond 1.5°C is now inevitable (in the next couple of decades) and the only way out is to cut emissions to bring temperatures down by the end of the century.
While the report may have sounded yet another clarion call for efforts to avoid breaching the warming limit set in the Paris Agreement, it stated that sustained efforts to reduce greenhouse gas emissions will most definitely limit climate change. Air quality will be the first to improve in such a scenario, while global temperatures would take 20-30 years to stabilise, according to the report.
Highlights of the report
“This report is a reality check,” said IPCC Working Group I Co-Chair Valérie Masson-Delmotte. “We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare.”
In the coming decades, once the 1.5°C warming limit has been crossed, the world should expect more heatwaves, longer summers and shorter winters. If the 2°C limit is breached, intense heatwaves will have a direct impact on health and agriculture. But it is not just temperature that is feeling the impact. The study pointed to other changes that the world must brace for with increased warming.
One of the worst impacts of climate change is being seen on earth’s water cycle. The rising intensity of rain and floods that have become regular headlines is a result of the vulnerable climate. Some of these impacts, such as rising sea levels in coastal areas, are irreversible and will continue throughout this century and will remain elevated for thousands of years, according to the report. It warned that extreme sea level events, which were only seen once in 100 years, are likely to occur every year by the end of the 21st century.
Global warming will amplify the melting of the glaciers and ice sheets, including those in the Arctic, the Antarctic and the Himalayas, which are already seeing a significant amount of ice loss. The report stated that even if emissions are brought down, these mountain and polar glaciers will continue to melt for decades or centuries.
The urban landscape will become more of a high-stress environment as a result of increased temperatures, the report found. It warns of a rise in heat stress, flooding from heavy rain and sea level rise in cities near the coast.
“Our message to every country, government, business and part of society is simple. The
next decade is decisive, follow the science and embrace your responsibility to keep the goal
of 1.5°C alive. We can do this together, by coming forward with ambitious 2030 emission reduction targets and long-term strategies with a pathway to net zero by the middle of the century, and taking action now to end coal power, accelerate the rollout of electric vehicles, tackle deforestation and reduce methane emissions,” said Alok Sharma, COP26 president.
The India scenario
The first instalment of the IPCC is focused more on the global impact of climate change. But these key findings are also relevant to India, which is the fourth-largest GHG emitter in the world.
The report envisioned a rise in frequency and severity of extreme heat events in India. Rainfall will also increase more severely in the southern part of India, according to the report. Rainfall could increase by 20%, relative to 1850-1900, on the southwest coast. A 4°C warming scenario could see a 40% increase in rain every year, the report stated.
“For India, the predictions in this report mean people labouring in longer and more frequent heat waves, warmer nights for our winter crops, erratic monsoon rains for our summer crops, destructive floods and storms that disrupt power supply for drinking water or medical oxygen production,” said Ulka Kelkar, director, Climate Program, World Resources Institute India (WRI).
Another key finding of the report was that reducing GHGs and other ‘short-lived climate forcers’ such as aerosols, particulate matter and methane emissions will have a two-fold positive effect–it will not only reduce air pollution, but also cut down warming levels. This has implications for India as well because the country has been struggling to bring down its air pollution levels. If the country finds a way to reduce these climate forcers, which have a short lifespan in the atmosphere, it could be a “win-win” situation for the climate and the health of Indian citizens.
The report’s conclusion that sea levels will continue to rise well into the 21st century also has an implication for India. The country includes a 7,517km coastline, which is already witnessing rising sea levels.
Another key finding on human influence driving the melting of glaciers since the 1990s is also significant for India. The Hindu Kush mountains in the Himalayas, which is already seeing rapid glacier loss, provides water supply to 240 million people, including 86 million Indians. The study stated that the glacier loss not only results in a rise in sea level, it could also trigger low-likelihood, high-impact outcomes for such regions in the future.
“Given that India is one of the most climate-vulnerable countries, we must recognise that even geographically faraway climatic changes can have consequences for our monsoons and intensity of extreme events. Our focus should be on building climate-resilient physical and digital infrastructure along with inculcating social and behavioural changes in citizens and communities,” said Dr Arunabha Ghosh, CEO, Council on Energy, Environment and Water (CEEW).
“Everything we need to avoid the exponential impacts of climate change is doable. But it depends on solutions moving exponentially faster than impacts, and getting on track to halving global emissions by 2030. COP26 will be the moment of truth,” said Christiana Figueres Founding Partner, Global Optimism & former Executive Secretary, UN Climate Change Convention.