Extreme heat and drought weakened forests’ ability to absorb carbon dioxide in 2024

The amount of carbon dioxide in Earth’s atmosphere rose at record speed in 2024, likely because rainforests and other ecosystems, stressed by extreme heat and drought, absorbed far less carbon than usual.

Sarah Kaplan reports for The Washington Post.


In short:

  • Data from the National Oceanic and Atmospheric Administration (NOAA) shows atmospheric CO₂ concentrations jumped 3.75 parts per million in 2024, the largest annual increase ever recorded, exceeding the previous 2015 record by 27%.
  • Though fossil fuel emissions hit a new high, scientists say this modest rise doesn’t account for the CO₂ spike; instead, they point to stressed forests, wildfires, and prolonged droughts disrupting the planet’s natural carbon sinks.
  • A recent El Niño event, followed by persistent dryness in the Amazon and central Africa, significantly diminished the land’s ability to absorb CO₂, potentially turning vital ecosystems into net carbon sources.

Key quote:

“This tropical dryness is basically shutting down CO₂ uptake.”

— Philippe Ciais, associate director of the Climate and Environmental Sciences Laboratory

Why this matters:

For decades, Earth’s forests, grasslands, and oceans have acted like a giant sponge, soaking up nearly half the carbon dioxide emitted by human activities. But when ecosystems like the Amazon rainforest and Congo Basin become stressed — by heat, drought, or fire — their ability to store carbon falters. That means more carbon stays in the atmosphere, accelerating climate change. In 2024, the world saw signs of that shift, as extreme weather events coincided with a breakdown in CO₂ absorption. If such patterns continue, the world could enter a dangerous feedback loop: warming damages ecosystems, which then release more carbon, which in turn speeds up warming. This would make it harder to predict or control climate outcomes, putting human health, food systems, and biodiversity at greater risk.

Read more: Forests struggle to absorb carbon due to extreme heat and wildfires

A view from below of a brick apartment building

Heat waves cost some Toronto residents more

Climate change is bringing more frequent heat waves to cities, but not all residents have equal access to space to cool down.

A view of a street with lots of flowering vines growing on the houses

Urban heat islands have solutions; many tropical cities can’t afford them

Urban heat islands pose a growing global health threat, but in tropical cities, the peril is surging.

A Black woman putting her voting record into a box at a polling station

In Arizona, the thermostat is driving voters to the polls

Record heat, two rate hikes and a data center boom have turned utility bills — not climate — into the state’s most volatile issue.
A closeup of a brown insect on a green leaf

Tick populations surge as the climate warms, and farmers bear the brunt

Farmers are at an elevated risk for tick-borne illnesses, which can have devastating health and economic consequences.
White government building with large decorative pillars

What to know about the Supreme Court’s major climate case this fall

The decision could set a significant precedent for states and cities trying to hold fossil fuel companies accountable for climate impacts.
A group of runners with numbered tags running on a city street

Hot weather forces marathons to consider changes to help runners

Marathon organizers are adjusting to warmer race conditions caused by climate change. Many races are shifting dates, starting earlier or offering shorter runs.
View from a group of aluminum soda cans from above, opened

US aluminum is poised for a comeback — if it overcomes these hurdles

Tariffs and rising grid demand are spurring a revival, but high electricity costs and community concerns threaten to stall key new smelter projects
From our Newsroom
Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

One facility has emitted cancer-causing chemicals into waterways at levels up to 520% higher than legal limits.

Regulators are underestimating health impacts from air pollution: Study

Regulators are underestimating health impacts from air pollution: Study

"The reality is, we are not exposed to one chemical at a time.”

Pennsylvania governor Josh Shapiro speaks with the state flag and American flag behind him.

Two years into his term, has Gov. Shapiro kept his promises to regulate Pennsylvania’s fracking industry?

A new report assesses the administration’s progress and makes new recommendations

silhouette of people holding hands by a lake at sunset

An open letter from EPA staff to the American public

“We cannot stand by and allow this to happen. We need to hold this administration accountable.”

wildfire retardants being sprayed by plane

New evidence links heavy metal pollution with wildfire retardants

“The chemical black box” that blankets wildfire-impacted areas is increasingly under scrutiny.

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.