Volunteers in dozens of countries were set to plant trees, clean up trash and urge governments to do more to combat climate change to mark Earth Day, as scientists warn of more extreme weather and record temperatures this year.

 

The run-up to the 54th annual celebration of the environment, officially marked on Saturday, has included a week of conservation and clean-up activities around the world, and festivals were due to begin in Rome and Boston on Friday.

 

Thousands were expected to gather in London on Friday to begin four days of events known as the "Big One", organised by the Extinction Rebellion activist group. A rally was to be staged in Washington urging President Joe Biden to commit to ending fossil fuel use.

 

On Saturday, volunteers will also begin major clean-up campaigns at Lake Dal in India's Srinigar and Florida's hurricane-hit Cape Coral.

 

On Thursday, Biden pledged to increase U.S. funding to help developing countries fight climate change and curb deforestation in Brazil's Amazon rainforest during a meeting with leaders from the world's largest economies.

 

U.N. Secretary General Antonio Guterres told countries attending Biden's Major Economies Forum that "a quantum leap in climate action" was required to limit temperature rises to 1.5 degrees Celsius. He warned in a recorded Earth Day message that "we seem hellbent on destruction".

 

Earth Day this year follows weeks of extreme weather with temperatures hitting a record 45.4 degrees Celsius (113.7 Fahrenheit) in Thailand and another punishing heatwave in India, where at least 13 people died of heatstroke at a ceremony last weekend.

 

Scientists warned this week that killer heatwaves were putting "unprecedented burdens" on India's agriculture, economy and public health, and undermining the country's long-term efforts to reduce poverty, inequality and illness.

 

Average global temperatures could hit record highs this year or in 2024, driven by climate change and the anticipated return of the "El Nino" weather phenomenon, climate scientists said on Thursday. (Reuters)