Former President Barack Obama warned the world Wednesday climate change would be worse than the Chinese coronavirus pandemic.

“We’ve all had to adapt to cope with a pandemic,” Obama wrote on Twitter. “Climate change will force far harsher changes on our kids.”

The president shared a story about young people who continue protesting the world’s failure to enact dramatic policies to reduce carbon emissions and shut down an oil-based economy in favor of one fueled by windmills and solar panels.

“All of us should follow the young people who’ve led the efforts to protect our planet for generations, and demand more of our leaders at every level,” Obama wrote.

We've all had to adapt to cope with a pandemic. Climate change will force far harsher changes on our kids. All of us should follow the young people who've led the efforts to protect our planet for generations, and demand more of our leaders at every level. https://t.co/uNueQl5bNX — Barack Obama (@BarackObama) April 22, 2020

The president has broken his silence on several political issues since the coronavirus pandemic began, criticizing President Trump’s handling of the crisis.

Obama argued that DACA illegal immigrants deserved amnesty during the coronavirus crisis and argued that more Americans should vote by mail.