Carbondioxide - Blog Posts

Pinpointing the Cause of Earth’s Recent Record CO2 Spike

A new NASA study provides space-based evidence that Earth’s tropical regions were the cause of the largest annual increases in atmospheric carbon dioxide concentration seen in at least 2,000 years.

What was the cause of this?

Scientists suspect that the 2015-2016 El Niño – one of the largest on record – was responsible. El Niño is a cyclical warming pattern of ocean circulation in the Pacific Ocean that affects weather all over the world. Before OCO-2, we didn’t have enough data to understand exactly how El Nino played a part.

Analyzing the first 28 months of data from our Orbiting Carbon Observatory (OCO-2) satellite, researchers conclude that impacts of El Niño-related heat and drought occurring in the tropical regions of South America, Africa and Indonesia were responsible for the record spike in global carbon dioxide.

These three tropical regions released 2.5 gigatons more carbon into the atmosphere than they did in 2011. This extra carbon dioxide explains the difference in atmospheric carbon dioxide growth rates between 2011 and the peak years of 2015-16.

In 2015 and 2016, OCO-2 recorded atmospheric carbon dioxide increases that were 50% larger than the average increase seen in recent years preceding these observations.

In eastern and southern tropical South America, including the Amazon rainforest, severe drought spurred by El Niño made 2015 the driest year in the past 30 years. Temperatures were also higher than normal. These drier and hotter conditions stressed vegetation and reduced photosynthesis, meaning trees and plants absorbed less carbon from the atmosphere. The effect was to increase the net amount of carbon released into the atmosphere.

In contrast, rainfall in tropical Africa was at normal levels, but ecosystems endured hotter-than-normal temperatures. Dead trees and plants decomposed more, resulting in more carbon being released into the atmosphere.

Meanwhile, tropical Asia had the second-driest year in the past 30 years. Its increased carbon release, primarily from Indonesia, was mainly due to increased peat and forest fires -  also measured by satellites.

We knew El Niños were one factor in these variations, but until now we didn’t understand, at the scale of these regions, what the most important processes were. OCO-2’s geographic coverage and data density are allowing us to study each region separately.

Why does the amount of carbon dioxide in our atmosphere matter?

The concentration of carbon dioxide in Earth’s atmosphere is constantly changing. It changes from season to season as plants grow and die, with higher concentrations in the winter and lower amounts in the summer. Annually averaged atmospheric carbon dioxide concentrations have generally increased year over year since the 1800s – the start of the widespread Industrial Revolution. Before then, Earth’s atmosphere naturally contained about 595 gigatons of carbon in the form of carbon dioxide. Currently, that number is 850 gigatons.

Carbon dioxide is a greenhouse gas, which means that it can trap heat. Since greenhouse gas is the principal human-produced driver of climate change, better understanding how it moves through the Earth system at regional scales and how it changes over time are important aspects to monitor.

Get more information about these data HERE.

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Carbon and Our Changing Climate

Carbon is the backbone of life on Earth. We are made of carbon, we eat carbon and our civilizations are built on carbon. We need carbon, but that need is also entwined with one of the most serious problems facing us today: global climate change.

Forged in the heart of aging stars, carbon is the fourth most abundant element in the Universe. Most of Earth’s carbon – about 65,500 billion metric tons – is stored in rocks. The rest is in the ocean, atmosphere, plants, soil and fossil fuels.

Over the long term, the carbon cycle seems to maintain a balance that prevents all of Earth’s carbon from entering the atmosphere, or from being stored entirely in rocks. This balance helps keep Earth’s temperature relatively stable, like a thermostat.

Today, changes in the carbon cycle are happening because of people. We disrupt the cycle by burning fossil fuels and clearing land. Our Orbiting Carbon Observatory-2 (OCO-2) satellite is providing our first detailed, global measurements of CO2 in the atmosphere at the Earth’s surface. OCO-2 recently released its first full year of data, critical to analyzing the annual CO2 concentrations in the atmosphere.

The above animation shows carbon dioxide released from two different sources: fires and massive urban centers known as megacities. The animation covers a five day period in June 2006. The model is based on real emission data and is then set to run so that scientists can observe how greenhouse gas behaves once it has been emitted.

All of this extra carbon needs to go somewhere. So far, land plants and the ocean have taken up about 55 percent of the extra carbon people have put into the atmosphere while about 45 percent has stayed in the atmosphere. The below animation shows the average 12-month cycle of all plant life on Earth (on land and in the ocean). Eventually, the land and oceans will take up most of the extra carbon dioxide, but as much as 20 percent may remain in the atmosphere for many thousands of years.

Excess carbon in the atmosphere warms the planet and helps plants on land grow more. Excess carbon in the ocean makes the water more acidic, putting marine life in danger. Forest and other land ecosystems are also changing in response to a warmer world. Some ecosystems -- such as thawing permafrost in the Arctic and fire-prone forests -- could begin emitting more carbon than they currently absorb. 

To learn more about NASA’s efforts to better understand the carbon and climate challenge, visit: http://www.nasa.gov/carbonclimate/.

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