Forests absorb 1.5 times the US CO2 Emissions per year

The net balance of carbon absorption / release processes by forests worldwide shows an extraction balance of 7.6 billion tons per year, 1.5 times the US emissions.Using ground, air, and satellite data, a diverse team of international researchers, including NASA scientists, has created a new method to assess how changes in forests over the past two decades have impacted carbon concentrations in the atmosphere.

In addition to better understanding the general role of forests in the global carbon cycle, scientists were also able to distinguish between the contributions of various types of forests, confirming that among forests, tropical forests are responsible for the largest component of global fluctuations. Carbon: both absorb more carbon than other types of forests and release more carbon into the atmosphere due to deforestation and degradation.

While land clearing for agriculture, industry and other human activities increases carbon dioxide in the atmosphere, the main cause of the global increase in carbon dioxide over the last century is human activities that burn fossil fuels such as coal. and oil. Together, trees and other plants extract carbon dioxide from the atmosphere.

The forest carbon flux map from the Global Forest Watch web application and the accompanying study published in Nature Climate Change on January 21 show these forest carbon fluctuations in unprecedented detail.

Through photosynthesis, forests absorb carbon dioxide from the atmosphere to produce oxygen, supplementing the collective respiration of other life on Earth that inhales oxygen and expels carbon dioxide.

According to the researchers, forests collectively absorbed around 15.6 billion metric tons of carbon dioxide from Earth’s atmosphere each year between 2001 and 2019, while deforestation, fires and other disturbances released an average of 8.1 billion metric tons. of carbon dioxide per year. Forests around the world are estimated to absorb about 7.6 billion metric tons, acting as a net carbon sink of about 1.5 times the annual emissions of the entire United States.

“Forests act like a two-lane highway in the climate system,” said lead researcher Nancy Harris, who serves as director of research for the World Resources Institute’s (WRI) Forest Program. “A detailed view of where both sides are happening (emissions and removals from forests) adds transparency to monitoring forest-related climate policies.”

This new methodology integrates data sets from numerous sources, including ground reports, aerial data, and satellite observations, to create the first coherent global framework for estimating carbon flux specifically for forests.

This is a change from the current annual national forest data report, which still varies between countries despite standardized guidelines from the Intergovernmental Panel on Climate Change (IPCC), often determined by the resources available in that region. Such non-uniformity in the data means that global carbon estimates can contain a considerable degree of uncertainty.

“The good news is that we know that there is uncertainty and that we can really quantify it,” says co-author Lola Fatoyinbo, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, in a statement. “All estimates come with an uncertainty around them, which will get smaller and smaller as we get better data sets.”

The biomass estimates for the study were based on data from NASA’s Ice, Cloud and Land Elevation Satellite (ICESat), which was primarily designed to track changes in ice sheet coverage, but also provides data from topography and vegetation.