Last month was the warmest September on record for planet

2020 has now seen three months of record global temperatures in January, May and September

Signs from Fridays for Future movement in Berlin, Germany. Ten cities joined New York and London in committing to divest from fossil fuel companies as part of efforts to combat climate change. AP

Climate activists march in an attempt to occupy the Garzweiler open-cast coal mine and nearby gas infrastructure on a day of civil disobedience near Grevenbroich, Germany. Getty

A child wears plastic bottle waste provided by climate and environmental activists during a protest in Nairobi, Kenya. Reuters

A deforested area close to Sinop, Mato Grosso state, Brazil. The number of bushfires raging in Brazil's Amazon increased 61 per cent in September last year, compared to the same period in 2019. AFP

Ice sculptures of Donald Trump and Jair Bolsonaro comprise the artwork 'Meltdown', which was on display last September during the UN Summit On Biodiversity in New York City. AFP

A Jaguar named Ousado, who suffered second-degree burns during fires in the South American Pantanal region, rests in his cage after treatment in Brazil. AP

Cars on the Golden Gate Bridge in San Francisco, California. The US state plans to phase out sales of new, petrol-powered cars by 2035. Bloomberg

Deadly bushfires in California burnt more than 16,000 square kilometres of land last year — more than double the previous record for the most land burnt in a single year in the state. AP

An aircraft prepares to drop fire retardant while battling a blaze in the Mendocino National Forest, California. AP

Filipino climate activists hold placards calling for climate action as a part of global climate change protests in Quezon City. Reuters

Debris collects in a river after heavy rains and floods hit Breil-sur-Roya, a French village close to the Italian border. AFP

Climate and environmental activists make their way through a forest next to the village of Shipunovo, 170 km south of the Siberian city of Novosibirsk, to extinguish a peat fire. AFP

A man holds a banner with the message "United for climate" during a small climate change protest in Brussels. AP

British zoologist Andrew Bladon takes the temperature of a butterfly near Pegsdon, England. Whether a butterfly's wings absorb or reflect heat from the sun could be a matter of life and death in a warming world, British researchers said. AFP

Members of an environmental group in Seoul, South Korea, take part in a protest against climate change. EPA

Activists from various environmental groups take part in a protest against climate change in New Delhi, India. EPA

Ugandan climate change activist Vanessa Nakate takes part in a demonstration in the Luzira suburb of Kampala, Uganda. Reuters

A climate change demonstration in Vienna, Austria. AFP

An iceberg floats past Bylot Island in the Canadian Arctic Archipelago in 2017. AP

A polar bear stands on the ice in the Franklin Strait in the Canadian Arctic Archipelago in 2017. AP

Earth's surface was warmer last month than any other September on record, the European Union's Earth Observation Programme said on Wednesday. Temperatures since January surpassed those of the hottest ever calendar year in 2016.

This year has now seen three months of record warmth - January, May and September - with June and April virtually tied for first, the Copernicus Climate Change Service (C3S) reported.

"There is currently little difference between 2020 and 2016 for the year-to-date," Copernicus senior scientist Freja Vambourg said.

For the 12-month period through September, the planet was nearly 1.3 degrees Celsius above pre-industrial levels.

That is alarmingly close to the 1.5°C threshold for severe impacts detailed in a major 2018 report by the UN's climate science advisory panel, the IPCC.

The Paris Agreement to combat climate change has enjoined nations to cap global warming at "well below" 2°C, and 1.5°C if feasible.

So far, Earth has warmed on average by one degree, enough to boost the intensity of deadly heatwaves, droughts and tropical storms made more destructive by the rising seas.

Climate change driven by greenhouse gas emissions from burning fossil fuels has picked up pace in recent decades.

Nineteen of the last 20 years are the warmest since accurate readings began in the late 19th century.

Since the late 1970s, the global thermometer has crept up 0.2°C every decade, according to EU data.

Temperatures in September were "exceptionally high" over northern Siberia, which - along with much of the Arctic Circle - has seen freakishly warm weather for months.

September was brutal in the Middle East, with new high temperatures reported in Turkey, Israel and Jordan.

Parts of North Africa and Tibet were also scorching hot, while maximum daytime values reached 49°C in Los Angeles County early in the month.

Mya-Rose Craig, 18, holds a cardboard sign reading "youth strike for climate" as she sits on the ice floe in the middle of the Arctic Ocean, September 20, 2020. Reuters

Across California, five of the state's six biggest wildfires in history were still burning at the end of the month.

"September was warmer by 0.05°C than September 2019, the previous (recorded) warmest September," the Copernicus report said.

Last month's global heat record was all the more remarkable because of the regional cooling effect of a naturally occurring La Nina weather event over the tropical Pacific ocean.

Arctic sea ice, meanwhile, shrank to its second lowest extent last month, slipping below four million square kilometres for only the second time since satellite records began in 1978, said C3S.

The Arctic ice cap floats on ocean water around the North Pole, and thus does not contribute directly to sea level rise when it melts.

But it does accelerate global warming. Freshly fallen snow reflects 80 per cent of the Sun's radiative force back into space.

But when that mirror-like surface is replaced by deep blue water, about the same percentage of Earth-heating energy is absorbed instead.

Climate change has also disrupted regional weather patterns, resulting in more sunshine beating down on the Greenland ice sheet, which is melting - and shedding mass into the ocean -  quicker than at any time in the last 12,000 years, according to a study last week.