Mumbai: The world will almost use up its carbon budget to keep temperature rise under 1.5°C by 2040, if average yearly carbon dioxide (CO2) emissions remain the same as they were in 2019, according to the newest report by the Intergovernmental Panel on Climate Change (IPCC), the United Nations body for assessing the science related to climate change.

This means that global warming will exceed the limit of 1.5°C before the end of the century, against what countries had agreed at the 21st Conference of Parties in Paris (COP) in 2015. This increase in temperature will lead to more frequent and intense climate-related risks like heat waves and floods.

“It is not like 1.5°C is a cliff and we are going to fall off it. It is clear that we will cross 1.5°C by next decade. Every increment is bad and so, howsoever much you can reduce, the better it is,” said Aditi Mukherji, director of the Climate Change Impact platform, Consultative Group on International Agricultural Research (CGIAR). “For India, while it is important to note that our per capita emissions are less but reality is that we are at the forefront of impacts. We simply cannot say we are not going to take action.”

Without a strengthening of policies to mitigate emissions, global warming of 3.2 [2.2–3.5]°C is projected by 2100, the IPCC report estimates.

“Climate resilient development becomes progressively more challenging with every increment of warming. This is why the choices made in the next few years will play a critical role in deciding our future and that of generations to come,” the IPCC report said.

This is the last report of the sixth assessment of climate change by IPCC, established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988. The reports provide political leaders with periodic scientific assessments concerning climate change, its implications and risks, as well as adaptation and mitigation strategies. The current session, leading up to the final report in this assessment session, was at Interlaken, Switzerland.

Some data points from the report:

  • If countries emit the same yearly CO2 emissions between 2020–2030 as they did in 2019, the resulting cumulative emissions would deplete, by 2030, more than a third of the remaining carbon budget for limiting global warming below 2°C (67% likelihood) by the end of the century.
  • For every gigatonne of carbon dioxide-equivalent (GtCO2) emitted by human activity, global surface temperature rises by 0.45°C.
  • Global surface temperature has increased faster since 1970 than in any other 50-year period over at least the last 2,000 years.
  • About 42% of historical cumulative net CO2 emissions have occurred between 1990 and 2019 and the remaining between 1850 and 1989.
  • In 2019, atmospheric CO2 concentrations (410 parts per million) were higher than at any time in at least 2 million years.
  • Concentrations of methane (1,866 parts per billion) and nitrous oxide (332 parts per billion) were higher than at any time in at least 800,000 years.
  • 10% of households with the highest per capita emissions contribute 34–45% of global consumption-based household GHG emissions, while the bottom 50% contribute 13–15%.

Wide ranging impacts

There are already signs of climate change across India, and the world. India saw an unusually hot February this year and March has been marked by unseasonal rains in many parts of the country.

Between 2010 and 2020, human mortality from floods, droughts and storms was 15 times higher in highly vulnerable regions, compared to regions with very low vulnerability. In all regions, increases in extreme heat events have resulted in human mortality and morbidity. The occurrence of climate-related food-borne and water-borne diseases and the incidence of vector-borne diseases have increased, the report said.

“In assessed regions, some mental health challenges are associated with increasing temperatures, trauma from extreme events, and loss of livelihoods and culture,” the report said. “Climate and weather extremes are increasingly driving displacement in Africa, Asia, North America, and Central and South America, with small island states in the Caribbean and South Pacific being disproportionately affected relative to their small population size.”

As warming levels increase, so do the risks of species extinction or irreversible loss of biodiversity in ecosystems, including forests, coral reefs and in Arctic regions. At sustained warming levels between 2°C and 3°C, the Greenland and West Antarctic ice sheets will be lost almost completely and irreversibly over multiple millennia, causing several metres of sea level rise, the IPCC report predicts.

Equity and climate finance

Though developing countries emit lower greenhouse gas emissions per capita than developed nations, they are more vulnerable to the impacts of global warming, and have fewer resources for mitigation and adaptation. In 2009, developed countries had pledged to deliver to developing countries an annual climate fund of $100 billion by 2020. But the $100 billion target itself is now inadequate because developing countries are estimated to need $600 billion a year from 2020 to 2050 to decarbonise just their energy sectors, IndiaSpend reported in October 2021.

At COP26, developed countries pledged to double finance towards climate adaptation by 2025 over what they had committed in 2019. Currently less than a quarter of climate finance is spent on it, IndiaSpend reported in November 2021.

At the COP27 in November 2022, in a win for developing countries, negotiators agreed to establish a finance facility to address climate-induced loss and damages faced by developing countries that are particularly vulnerable to the impacts of climate change. But the details of the facility, along with the total corpus, will be finalised at the next climate conference (COP28) in the United Arab Emirates in 2023.

Developing countries’ demand for enhanced climate finance also found echoes in the IPCC report.

“Although global tracked climate finance has shown an upward trend, current global financial flows for adaptation… are insufficient and constrain implementation of adaptation options, especially in developing countries,” the report noted.

In addition, the report said, the impacts of climate change and extreme weather affect countries’ abilities to undertake adaptation, particularly in developing and least developed countries. The 46 least developed countries, with a combined population of more than one billion people, are most vulnerable to the impacts of climate change, such as sea-level rise, desertification, fires, floods and droughts. These impacts have economic repercussions, further limiting the ability of these resource-constrained countries to finance measures to improve their resilience to climate change.

It's not just finance, but policies and economic structures that also have to change, said Joyashree Roy of the Energy Economic Programme at the Asian Institute of Technology. “One very important message that came out of this report was there are going to be disruptive changes in economic structures due to the move from high carbon to low carbon sources…Here, policies that shield the poor and vulnerable are extremely important.”

For instance, as India moves from coal to renewable energy, it will have to ensure a just energy transition for communities that work on coal mines and related industries, and for communities that live on land where large renewable projects are coming up. For example, as Gujarat’s Modhera village shifted from thermal energy to solar power, the transition hit pastoralists in neighbouring Sujanpura village, we reported in March 2023.

“In 2018, IPCC highlighted the unprecedented scale of the challenge required to keep warming to 1.5°C. Five years later, that challenge has become even greater due to a continued increase in greenhouse gas emissions,” the IPCC said in a press release. “The pace and scale of what has been done so far, and current plans, are insufficient to tackle climate change.”

We welcome feedback. Please write to We reserve the right to edit responses for language and grammar.