![Doesn't carbon dioxide in the atmosphere come from natural sources?](/sites/default/files/douglas_fire_usda_480.jpg)
Yes, there are, but the only new process on Earth that has been identified that can account for the significant tipping of Earth's carbon balance is human activity, including deforestation, biomass burning, cement production, and—especially—fossil-fuel emissions.
![Climate.gov tweet chat: Talk with experts about ongoing NASA/NOAA field campaign to study smoke from wildfires and agricultural burning](/sites/default/files/FIREX_AQ_smokePyroCB.jpg)
If you missed our August 29 tweet chat, here's the transcript. Read what the fire and smoke experts had to say about the FIREX-AQ field campaign and its mission to study what's in the smoke from wildfires and agricultural burning.
![Even with global warming, extremely hot summers would be less frequent if it weren’t for deforestation](/sites/default/files/HotDryReturnTime_EastWest_LCC_480x320.png)
Across much of the mid-latitudes, models estimate that the converting forests to farms and rangeland shortened the return period for extremely hot, dry summers: from every 10 years to every 2-3 years.
![Local group fortifying Chicago's urban forest and building city's climate resilience](/sites/default/files/ChicagoTrain_Rotater.png)
Trees within a city can help reduce urban heat, control stormwater, and provide habitat to local wildlife. As climate conditions change, a Chicago group is working to enhance the reilience of the city's urban forest.
![Map image for Climate connections to Fort McMurray fire](/sites/default/files/styles/width_320/public/FT.-MCMURRAYFIRE_620.png?itok=oNurXCMJ)
Climate connections to Fort McMurray fire
May 12, 2016
![Photo of the Amazon river and surrounding jungle](/sites/default/files/styles/card_thumb/public/2023-07/amazon_aerial_river_480.jpg?itok=hvz1z72u)
How drought affects carbon balance in the Amazon
March 6, 2014