After years of drought followed by torrential rains, East Africa is devastated by the biggest swarm of locusts in decades. Billions of the ravenous insects devour crops in Ethiopia, Kenya and Somalia, spreading to southern Africa, Yemen and India in later months. Climate scientists say heavy rains and warmer temperatures linked to climate change are to blame for "exceptional" breeding conditions.

A long bushfire season comes to an end after more than six months. Thirty-three people and 3 billion animals are dead, hurt or displaced, and an area the size of South Korea has been devastated. Prime Minister Scott Morrison rejects a direct link between greenhouse gas emissions and the severity of the fires; Australia is one of the world's highest per capita emitters of carbon dioxide.

With more than half the global population under lockdown due to the COVID-19 pandemic, global greenhouse gas emissions slow. Skies above industrial centers in China, Italy and elsewhere clear as airlines slash flights, factories shut down and city streets empty out. But as lockdowns ease and people find ways to live with the pandemic, experts warn emissions may rebound.

As researchers race to develop a COVID-19 vaccine, world leaders struggle to deal with the economic fallout of the pandemic. Chancellor Angela Merkel announces that Germany plans to make climate-friendly investment a priority in its recovery plans and urges global decision-makers to do the same. Meanwhile, activists keep up the pressure with protests, both virtual and physically distanced.

The first pandemic wave begins to ebb and people — some cooped up for weeks — begin to venture outdoors. To help maintain physical distancing and keep traffic jams and public transport crowds from getting out of control, many cities introduce temporary or permanent measures to improve urban mobility. Bogota, Colombia (above) adds more than 100 kilometers (62 miles) of emergency bike lanes.

The ongoing pandemic isn't just a health disaster. Use of disposable face masks, gloves and other plastic products has skyrocketed, contributing to a growing waste problem. In a related attempt to clean up the mess and move away from a "throw-away culture," Germany falls in line with the EU and decides to ban plastic cutlery, straws, food containers and other single-use products as of July 2021.

Early in the summer, Russia declares a state of emergency after some 21,000 tons of diesel fuel are leaked, contaminating local rivers and soil in Siberia. The disaster is followed by uncontrolled wildfires across the region, one of the world's coldest. Smoldering permafrost and burning brush release more than half a billion tons of carbon dioxide into the atmosphere the following months.

Back-to-back hurricanes in the Caribbean; raging wildfires in the Amazon rainforest; historic floods in Southeast Asia: The increasingly devastating effects of climate change make themselves known. Hurricane Laura, which caused intense flooding in the Dominican Republic and Haiti (above), claims dozens of lives there and in the US. Pakistan, meanwhile, sees its worst flooding since 1931.

As China makes an unexpected announcement to become climate neutral by 2060, wildfires rage across the US west coast, casting an ominous orange glow over San Francisco and the Bay Area. The fires scorch the states of Oregon, Washington and California for months. Overall, fires in the US claimed an estimated 4,177,856 acres (1,690,718 hectares) of land in 2020, more than half the size of Belgium.

Conservation groups reveal that the Tasmanian devil has made an appearance on the Australian mainland for the first time in 3,000 years. The "historic" release of the carnivorous marsupials into a sanctuary north of Sydney will give the endangered species the chance to rebuild a self-sustaining wild population. It's estimated that fewer than 25,000 devils still live in the wild.

The US officially leaves the Paris Agreement — a day after the decisive win of Joe Biden and Kamala Harris in the presidential election. Biden pledges to rejoin the international climate accord when he takes office in January and announces ambitious plans — and trillions in funding — to help wean the US energy sector off fossil fuels over the next 15 years and achieve net-zero emissions by 2050.

As the world marks five years since the signing of the Paris Agreement, the EU ups its green credentials. After months of tough negotiations, and a prior endorsement by the European Parliament, the 27 member states agree to a binding target to cut carbon emissions by at least 55% by 2030 compared to 1990 levels — up from 40%. Campaigners welcome the move but say much more still needs to be done.