2011-2020 warmest decade on record; each decade since 1990s warmer than last one

New Delhi: The decade of 2011-2020 was the warmest decade on record, the World Meteorological Organisation (WMO) said on Tuesday. Global mean temperature for the period 2011-2020 was 1.10 degree C above the pre-industrial average.

Each successive decade since the 1990s has been warmer than all previous decades.

The warmest years of the decade were 2016 because of a strong El Niño event, and 2020. The WMO had earlier forecast that 2023 is likely to set the record for the warmest year ever. The largest positive anomalies for the decade, in places more than 2 degree C above the 1981-2010 average, were in the Arctic, WMO said.

The continued rising concentrations of greenhouse gases fuelled record land and ocean temperatures and turbo-charged a dramatic acceleration in ice melt and sea level rise, according to a new report by WMO.

Glaciers thinned by around 1 metre per year - an unprecedented loss – with long-term repercussions for water supplies for millions of people. The Antarctic continental ice sheet lost nearly 75% more ice between 2011-2020 than it did in 2001-2010 – a worrying development for future sea level rise which will jeopardise the existence of low-lying coastal regions.

“Each decade since the 1990s has been warmer than the previous one and we see no immediate sign of this trend reversing. More countries reported record high temperatures than in any other decade. Our ocean is warming faster and faster and the rate of sea level rise has nearly doubled in less than a generation. We are losing the race to save our melting glaciers and ice sheets. This is unequivocally driven by greenhouse gas emissions from human activities,” said WMO Secretary-General, Petteri Taalas.

“We have to cut greenhouse gas emissions as a top and overriding priority for the planet in order to prevent climate change spiralling out of control,” Taalas added.

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In a glimmer of hope, the report said that the Antarctic ozone hole was smaller in the 2011-2020 period than during the two previous decades thanks to successful and concerted international action to phase out ozone depleting chemicals, an indication of the success of the Montreal Protocol.

“Our weather is becoming more extreme, with a clear and demonstrable impact on socio-economic development. Droughts, heatwaves, floods, tropical cyclones and wildfires damage infrastructure, destroy agricultural yields, limit water supplies and cause mass displacements,” said Taalas. “Numerous studies show that, in particular, the risk of intense heat has significantly increased in the past decade.”

The report-- Decadal State of the Climate 2011-2020 -- documents how extreme events across the decade had devastating impacts, particularly on food security, displacement and migration, hindering national development and progress toward the Sustainable Development Goals (SDGs).

This is based on the average of six data sets used by WMO. The warmest six years on record globally were between 2015 and 2020.

There is positive news too: The number of casualties from extreme events has declined, associated with improved early warning systems.

But, economic losses associated with extreme events have increased.A major contributor to the decrease in mortality during disasters has been improved early warning systems, driven by improvements in forecasting, coupled with improved disaster management. The 2011-2020 decade was the first since 1950 when there was not a single short-term event with 10,000 deaths or more.

However, economic losses from extreme weather and climate events have continued to increase. While in 200Hurricane Katrina 5 remains the world’s most costly weather disaster, the next four most costly events were all hurricanes that occurred in the 2011-2020 decade, and whose greatest impacts were in the United States and/or its territories.