Activists and scientists worldwide, mostly prevented from demonstrating publicly because of the coronavirus pandemic, marked the 50th anniversary of Earth Day with online events on Wednesday, and their message was largely one of warning: When this health crisis passes, world leaders must rebuild the global economy on a healthier, more sustainable track.
That was highlighted by an influential scientific body, the World Meteorological Organization, which forecast that the pandemic would drive down global greenhouse gas emissions by 6 percent this year, the biggest yearly decline in planet-warming carbon dioxide since the Second World War. But the group said that would be nowhere near the reductions needed to avoid the most devastating impacts of climate change.
The agency went on to caution that, while the short-term reductions are largely a result of the sharp decline in transportation and industrial energy production, emissions are likely to rise in the coming years unless world leaders take swift action to address climate change.
“Whilst Covid-19 has caused a severe international health and economic crisis, failure to tackle climate change may threaten human well-being, ecosystems and economies for centuries,” said Petteri Taalas, a former research scientist from Finland and now the meteorological organization’s general secretary.
The last five years have already been the hottest on record, the agency said, and a new global heat record is expected to be set in the next five years. (Scientists with the National Oceanic and Atmospheric Administration said recently that there was a high likelihood that 2020 would be a record hot year.)
But how fast the world warms up depends to a large degree on what happens in the coming weeks and months, as lawmakers in major world capitals wrangle over economic stimulus packages to the tune of many trillions of dollars.
The head of the United Nations, António Guterres, called on countries to transition away from fossil fuels as they repair their economies, including by suspending taxpayer funds to prop up polluting industries and instead using them to create “green jobs and sustainable growth.”
“We need to turn the recovery into a real opportunity to do things right for the future,” Mr. Guterres said.
His administration has rolled back a raft of environmental protections and announced its exit from the Paris climate accord, which is designed to slow down the rate of global temperature rise and avert the worst effects of climate change.
The coronavirus pandemic, which has claimed around 180,000 lives, came at a time when attention to climate change had risen globally. Children and teenagers had launched worldwide protests, demanding that presidents and prime ministers take climate action. The titans of business and finance had unveiled pledges to reduce their carbon footprints, and BlackRock, the world’s largest asset manager, with $7 trillion in global investments, announced that it would start pulling its money from ventures with high levels of climate risk. For the first time, climate change policies had begun to figure prominently in the United States presidential election campaign.
Then came the pandemic, which, as Greta Thunberg, the 17-year-old climate activist, put it, “turned everything upside down.”
“Whether we like it or not, the world has changed,” she said Wednesday from the Nobel Museum in Stockholm, her home city. “It looks completely different from how it did a few months ago and it will probably not look the same again and we are going to have to choose a new way forward.”
Khristen Hamilton, 18, an organizer with a youth activist group called Zero Hour, said her organization had been forced to drop plans for an ambitious bus tour and in-person voter registration drive. Now, the group is running the registration effort online and hosting weekly webinars on what it calls the roots of the climate crisis.
“We just had to do a pivot,” Ms. Hamilton said from McLean, Va., where she lives. “My generation of organizers know how to efficiently organize online, which is a good thing.”