What the hottest September ever reveals about climate change

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The record-breaking temperatures in September come on the back of several similar records for other months this year. In fact, July this year was not just the warmest July, it was the warmest for any month. That means that the average global monthly temperature has never been as high as in July this year. Several days in that month broke the daily temperature records.

Before that, June was the warmest June ever, while February, March, April and May all recorded average temperatures that were in the top-five highest ever brackets for those respective months.

In addition, the three-month period between June and August was the warmest ever on record, during which temperatures everywhere across the world — not just the global average — reached levels that were made at least two times more likely by climate change.

Even in this grim scenario, September managed to carve out another dubious distinction. The average global temperature for September was 1.75 degree Celsius warmer than the average of the 1850-1900 period, the pre-industrial time that is usually considered the baseline for measuring temperature changes. No other month, not even July this year, showed such a large deviation from the pre-industrial average.

September was very warm even when compared to a more contemporary baseline — 0.93 degree Celsius hotter than the average of the 1991-2020 period.

“Since June, the world has experienced unprecedented heat on land and sea. The temperature anomalies are enormous – far bigger than anything we have ever seen in the past. The Antarctic winter sea ice extent was the lowest on record for the time of year. What is especially worrying is that the warming El Niño event is still developing, so we can expect these record-breaking temperatures to continue for months, with cascading impacts on our environment and society,” said Secretary-General of World Meteorology Organisation, Petteri Taalas.

The reason scientists are expecting 2023 to emerge as the warmest year ever is that the average temperature of the first nine months is already higher than the corresponding period of 2016, which is the warmest year on record so far. Average temperature for the year 2016 was 1.28 degree Celsius higher than the pre-industrial times. And it is feared that 2023 might breach the 1.5 degree Celsius mark for the first time.

“The average global temperature for the first nine months of 2023 (January–September) is 0.52°C higher than the corresponding 1991-2020 average, and 0.05°C higher than the nine-month average for 2016, currently the warmest calendar year on record,” a statement from the Copernicus Climate Change service, run on behalf of the European Commission, said.

Little to do in the short term

The series of record-breaking temperature events this year has attracted huge attention in the scientific community, which has been repeatedly flagging it as something completely abnormal even when seen in the context of steadily rising temperatures in the past few years. Many of the heat-wave events this year, including one in the unlikely month of April, have been attributed to climate change by scientific studies.

But this hasn’t triggered any policy response from countries, in the form of strengthened climate actions.

To be sure, there is little that human beings can do to bring down the temperatures next month or next year. There is no climate action that can arrest the rise of temperatures, or prevent the recurrence of such warming events, in the short term. Only a massive global disruption, something like the one caused by the Covid pandemic, is capable of making any appreciable deviation in the current trend over a short period of time.

But the extraordinary warming events of this year have not been able to instil any special sense of urgency in the planet’s plan of action to deal with climate change. The world is almost certain to breach the 1.5 degree Celsius target in the next four years, according to an assessment by the World Meteorological Organisation, if not this year itself.

The only clear deliverable from the climate discussions this year has been the promise to triple the renewable energy installed capacity, from its current levels, by 2030. This was one of the outcomes of the G20 meeting in New Delhi last month. The International Energy Agency estimates that this single measure could result in an avoidance of 7 billion tonnes of carbon dioxide emissions by 2030. But this, even if achieved, would be too little. Assessments show that greenhouse gas emissions in 2030, according to current trajectories, would exceed the 1.5 degree Celsius compatible levels by at least 24 billion tonnes by 2030.

At the annual climate change meeting, scheduled to be held in Dubai this year, countries are supposed to do a stock-take exercise of the global climate action, and assess its adequacy in the context of the 1.5 and 2 degree Celsius temperature goals. The big gaps likely to be revealed by the stock-take exercise are expected to spur some more energetic climate action from countries.