Carbon and Climate

The North American Forest Dynamics (NAFD) study provides annual maps of forest disturbance in the conterminous United States, from 1986-2010. Using data from the NASA/USGS Landsat satellite program, the NAFD study produces maps at a spatial resolution of 30-meters. Spanning the 25 years of the study required 26,142 Landsat images and the use of the NASA Earth Exchange (NEX) supercomputing facility. Each annual map has classified pixels showing water, no forest cover, forest cover, no data available (data gaps) in present year, and forest disturbances that occurred in that year. Forest distubance, in this study, refers to any removal or loss of the forest canopy. There were disturbances from natural causes, such as fires, insect outbreaks, hurricanes, tornadoes, and snow storms. There were also human-caused disturbances such as timber harvesting, urban development, and mining. Major timber harvest areas included the Southeast, the Pacific Northwest, and Maine. Extensive mountaintop mining was found in the Southern Appalachians, extending from Western Virginia to Tennessee. The eastern coast suffered substantial damages from hurricanes, while large scale damages from fire and insect outreak were mostly in the western U.S. This study is a core project of the North American Carbon Program (NACP), a multidisciplinary research program designed to obtain scientific understanding of North America’s carbon sources and sinks and quantify changes in carbon stocks. This information is being used to evaluate the role of forest disturbance in the North American carbon cycle, which will help meet societal concerns and provide tools for decision makers. The NAFD (North American Forest Dynamics) study, a core project of the North American Carbon Program (NACP), was supported by grants from NASA’s Terrestrial Ecology, Carbon Cycle Sciences, and Applied Sciences Programs. The UMD group was supported under NASA Grant NNX11AJ78G S01. Associated NAFD-NEX activities have been carried out by Warren Cohen, USFS Pacific Northwest Research Station (Product Validation), Jeffrey Masek, NASA Goddard Space Flight Center (Regrowth Dynamics), Gretchen Moisen, USFS Rocky Mountain Research Station (Causal Factors Attribution) and Ramakrishna Nemani, NASA Ames Research Center (NEX computing). Data Citation: Goward, S.N., C. Huang, F. Zhao, K. Schleeweis, K. Rishmawi, M. Lindsey, J.L. Dungan, and A. Michaelis. 2015. NACP NAFD Project: Forest Disturbance History from Landsat, 1986-2010. ORNL DAAC, Oak Ridge, Tennessee, USA. http://dx.doi.org/10.3334/ORNLDAAC/1290

In this animation, NASA instruments show the seasonal cycle of vegetation and the concentration of carbon dioxide in the atmosphere. The animation begins on January 1, when the northern hemisphere is in winter and the southern hemisphere is in summer. At this time of year, the bulk of living vegetation, shown in green, hovers around the equator and below it, in the southern hemisphere.

As the animation plays forward through mid-April, the concentration of carbon dioxide, shown in orange-yellow, in the middle part of Earth's lowest atmospheric layer, the troposphere, increases and spreads throughout the northern hemisphere, reaching a maximum around May. This blooming effect of carbon dioxide follows the seasonal changes that occur in northern latitude ecosystems, in which deciduous trees lose their leaves, resulting in a net release of carbon dioxide through a process called respiration. Carbon dioxide is also released in early spring as soils begin to warm. Almost 10 percent of atmospheric carbon dioxide passes through soils each year.

After April, the northern hemisphere moves into late spring and summer and plants begin to grow, reaching a peak in the late summer. The process of plant photosynthesis removes carbon dioxide from the air. The animation shows how carbon dioxide is scrubbed out of the atmosphere by the large volume of new and growing vegetation. Following the peak in vegetation, the drawdown of atmospheric carbon dioxide due to photosynthesis becomes apparent, particularly over the boreal forests.

Note that there is roughly a three-month lag between the state of vegetation at Earth's surface and its effect on carbon dioxide in the middle troposphere.

Data like these give scientists a new opportunity to better understand the relationships between carbon dioxide in Earth's middle troposphere and the seasonal cycle of vegetation near the surface.

Creating the Animation

This animation was created with data taken from two NASA spaceborne instruments. The concentration of carbon dioxide data from the Atmospheric Infrared Sounder (AIRS), a weather and climate instrument that flies aboard NASA's Aqua spacecraft, is overlain on measurements of vegetation index from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, also on NASA's Aqua spacecraft, to better understand how photosynthesis and respiration influences the atmospheric carbon dioxide cycle over the globe. The animation runs from January through December and repeats. The AIRS tropospheric carbon dioxide seasonal cycle values were made by averaging AIRS data collected between 2003 and 2010, from which the annual carbon dioxide growth trend of 2 parts per million per year has been removed. For example, the data used for January 1 is actually an average of eight years of AIRS carbon dioxide data taken each year on January 1. The vegetation values were made using data averaged over a four-year period, from 2003 to 2006.

Further Detail

AIRS uses infrared technology to determine the concentration of atmospheric water vapor and several important trace gases as well as information about temperature and clouds. AIRS orbits Earth from pole-to-pole at an altitude of 438 miles (705 kilometers), measuring Earth's infrared spectrum in 3,278 channels spanning a wavelength range from 3.74 microns to 15.4 microns. Originally designed to improve weather forecasts, AIRS has improved operational five-day weather forecasts more than any other single instrument over the past decade. AIRS has also been found to be sensitive to atmospheric carbon dioxide in the middle troposphere, at an altitude of 5 to 10 kilometers or 3 to 6 miles. AIRS is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena. For further information, access the AIRS project

The MODIS instrument is managed by NASA's Goddard Space Flight Center, Greenbelt, Md. For further information, access the MODIS project.

This visualization leads viewers on a narrated global tour of fire detections beginning in July 2002 and ending July 2011. The visualization also includes vegetation and snow cover data to show how fires respond to seasonal changes. The tour begins in Australia in 2002 by showing a network of massive grassland fires spreading across interior Australia as well as the greener Eucalyptus forests in the northern and eastern part of the continent. The tour then shifts to Asia where large numbers of agricultural fires are visible first in China in June 2004, then across a huge swath of Europe and western Russia in August, and then across India and Southeast Asia through the early part of 2005. It moves next to Africa, the continent that has more abundant burning than any other. MODIS observations have shown that some 70 percent of the world's fires occur in Africa alone. In what's a fairly average burning season, the visualization shows a huge outbreak of savanna fires during the dry season in Central Africa in July, August, and September of 2006, driven mainly by agricultural activities but also by the fact that the region experiences more lightning than anywhere else in the world. The tour shifts next to South America where a steady flickering of fire is visible across much of the Amazon rainforest with peaks of activity in September and November of 2009. Almost all of the fires in the Amazon are the direct result of human activity, including slash-and-burn agriculture, because the high moisture levels in the region prevent inhibit natural fires from occurring. It concludes in North America, a region where fires are comparatively rare. North American fires make up just 2 percent of the world's burned area each year. The fires that receive the most attention in the United States, the uncontrolled forest fires in the West, are less visible than the wave of agricultural fires prominent in the Southeast and along the Mississippi River Valley, but some of the large wildfires that struck Texas earlier this spring are visible.

More information on the Fire Information for Resource Management (FIRMS) is available at http://maps.geog.umd.edu/firms/.

Twelve years of global deforestation, wildfires, windstorms, insect infestations, and more are captured in a new set of forest disturbance maps created from billions of pixels acquired by the imager on the NASA-USGS Landsat 7 satellite. The maps are the first to measure forest loss and gain using a consistent method around the globe at high spatial resolution, allowing scientists to compare forest changes in different countries and to monitor annual deforestation. Since each pixel in a Landsat image represents a piece of land about the size of a baseball diamond, researchers can see enough detail to tell local, regional and global stories.

Hansen and colleagues analyzed 143 billion pixels in 654,000 Landsat images to compile maps of forest loss and gain between 2000 and 2012. During that period, 888,000 square miles (2.3 million square kilometers) of forest was lost, and 308,900 square miles (0.8 million square kilometers) regrew. The researchers, including scientists from the University of Maryland, Google, the State University of New York, Woods Hole Research Center, the U.S. Geological Survey and South Dakota State University, published their work in the Nov. 15, 2013, issue of the journal Science.

Key to the project was collaboration with team members from Google Earth Engine, who reproduced in the Google Cloud the models developed at the University of Maryland for processing and characterizing the Landsat data; Google Earth Engine contains a complete copy of the Landsat record. The computing required to generate these maps would have taken 15 years on a single desktop computer, but with cloud computing was performed in a few days.

Since 1972, the Landsat program has played a critical role in monitoring, understanding and managing the resources needed to sustain human life such as food, water and forests. Landsat 8 launched Feb. 11, 2013, and is jointly managed by NASA and USGS to continue the 40-plus years of Earth observations.

To view the forest cover maps in Google Earth Engine, visit: http://earthenginepartners.appspot.com/google.com/science-2013-global-forest

Deforestation transforms Brazil's backcountry.

Satellite instruments reveal the yearly cycle of plant life on the land and in the water. On land, the images represent the density of plant growth, while in the oceans they show the chlorophyll concentration from tiny, plant-like organisms called phytoplankton. From December to February, during the northern hemisphere winter, plant life in the higher latitudes is minimal and receives little sunlight. However, even in the mid latitudes plants are dormant, shown here with browns and yellows on the land and dark blues in the ocean. By contrast the southern ocean and land masses are at the height of the summer season and plant life is revealed with dark green colors on the land and in the ocean. As the year progresses, the situations reverses, with plant life following the increased sunlight northward, while the southern hemisphere experiences decreased plant actvity during its' winter. Rather than showing a specific year, the animation shows an average yearly cycle by combining data from many satellite instruments and averaging them over multiple years.

Phytoplankton are microscopic organisms that live in watery environments, forming the foundation of the aquatic and marine food webs. Phytoplankton populations can grow explosively creating bright green and blue marble swirls, or blooms, near the surface. This visualization shows global daily averages of suspended particulate inorganic carbon (PIC, known as calcium carbonate or limestone) from July 4, 2002 to May 26, 2014, made with data from Aqua/MODIS. One can see shades of bright turquoise circling the Southern Ocean, a unique and consistent feature characterized by the presence of elevated PIC concentrations near the Sub-Tropical, Sub-Antarctic, and Polar Fronts. Referred to as the "Great Calcite Belt," high PIC concentrations result from large numbers of highly reflective microscopic PIC plates called “coccoliths,” released from calcifying coccolithophores. Such regions of elevated reflectance have been observed each year during austral summer with minor variations from year to year. Many sectors of the Southern Ocean are generally characterized by low concentrations of potentially growth limiting iron (Fe) concentrations. Studies suggest, however, that coccolithophores are well adapted to growth under low ambient iron conditions.

The global average carbon dioxide concentration increased from 374 to 383 parts per million from Sep. 2002 to Sep. 2006.

Broadcast quality interviews with scientists involved in NASA's Carbon and Climate press briefing.

Earth’s land and ocean currently absorb about half of all carbon dioxide emissions from the burning of fossil fuels, but it’s uncertain whether the planet can keep this up in the future. NASA’s Earth science program works to improve our understanding of how carbon absorption and emission processes work in nature and how they could change in a warming world with increasing levels of carbon dioxide and methane emissions from human activities. Later this month, the United Nations climate meeting in Paris (Conference of Parties, aka COP-21) will focus on setting limits on future levels of human-produced carbon emissions. NASA hosted a media teleconference at noon EST on Thursday, Nov. 12, to discuss the latest insights into how Earth is responding to rising levels of heat-trapping gases in the atmosphere, and what this means for our future climate. This video features George Hurtt, lead for NASA’s Carbon Monitoring System, and professor at University of Maryland, discussing the key points he delivered on the telecon.

Earth’s land and ocean currently absorb about half of all carbon dioxide emissions from the burning of fossil fuels, but it’s uncertain whether the planet can keep this up in the future. NASA’s Earth science program works to improve our understanding of how carbon absorption and emission processes work in nature and how they could change in a warming world with increasing levels of carbon dioxide and methane emissions from human activities. Later this month, the United Nations climate meeting in Paris (Conference of Parties, aka COP-21) will focus on setting limits on future levels of human-produced carbon emissions. NASA hosted a media teleconference at noon EST on Thursday, Nov. 12, to discuss the latest insights into how Earth is responding to rising levels of heat-trapping gases in the atmosphere, and what this means for our future climate. This video features Lesley Ott, research scientist in the Global Modeling and Assimilation Office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, discussing the key points she delivered on the telecon.

Rising carbon dioxide levels in the atmosphere are driving changes in Earth’s climate. But scientists are still trying to answer important questions about how carbon dioxide emissions get absorbed by the land and the ocean — and how this could change in the future. NASA Jet Propulsion Laboratory’s Annmarie Eldering shares how the Orbiting Carbon Observatory-2 is helping answer these questions on a global scale.

Jeremy Werdell is studying how microscopic plankton in the oceans are responding to our changing climate. As a scientist at NASA’s Goddard Space Flight Center, he knows that Earth's oceans and land cover have been doing us a favor. As people burn fossil fuels and clear forests, only half of the carbon dioxide released stays in the atmosphere, warming and altering Earth’s climate. The other half is removed from the air by the planet’s vegetation ecosystems and oceans. But Jeremy and other scientists are still trying to answer important questions about how carbon dioxide emissions get absorbed by the land and the ocean — and how this could change in the future. Later this month, the United Nations climate meeting in Paris (Conference of Parties, aka COP-21) will focus on setting limits on future levels of human-produced carbon emissions.