by Isabel Ovalle
Nasa, the National Aeronautics and Space Administration of the US, puts its experts, technology and satellites to use for the evaluation of the impact of climate change on Earth.
Among these satellites is the Landsat programme, which recently celebrated its 40th anniversary. Since the launch of the first satellite in 1972, multispectral digital images of the global land surface have been collected and archived.
With the 8th Landsat to be launched in February 2013, the programme will continue providing scientific measurements to accurately track land surface conditions and how they change.
These images are collected at a scale that can differentiate natural variation from human impact. Urban growth of cities, health and disturbance of forests, recession of the world’s glaciers and water supply and productivity of agriculture are examples of how Landsat can capture and characterize land surface conditions.
Jack A Kaye, associate director for Research of Science Mission Directorate of Nasa, travelled to Doha to share his expertise. He said that “with satellites we have a pretty good sense of what’s going on anywhere in the world.”
“We can look at the results and understand what’s happening to this planet in relation to temperature and precipitation. We are trying to launch a satellite in 2013 to measure soil moisture and we’ll launch another one in 2014 to improve our ability to measure precipitation,” he added.
Satellites also measure solar radiation. “If you have data you can begin to make connections, look at pollutants,” added Kaye. Currently Nasa has 16 satellite missions that are studying the Earth and the sun. In addition, the agency has partnerships with European nations and Canada, among others.
“Nasa is blessed with being a science agency that’s in the position to develop technology, build satellites, and fly planes. We try to work in partnership with others in the US and other space agencies,” continued the Nasa official.
In due course, the agency aims to “provide tools to help people in a number of cases, one of the biggest challenges is to process all the data, a task which becomes a burden because it’s so much,” he said.
Doha’s conference is the third one with Nasa participation at the US center. Kaye explained that “the climate problem is a global problem, there are things that can only be studied from space, like the thaw in Greenland and Antarctica. It’s impossible to imagine how one could do that without satellites which make it possible to address things that otherwise wouldn’t be.”
Kaye said that “even though climate is an area of political sensitivity, science gives as the rigorous base to make decisions for the future.”
“It’s a great way to train people, help them learn about the world, and about the science. It’s hard sometimes to think about change. One thing we know is that the earth doesn’t do the same thing everywhere. If you really want to know how the Earth as a planet is behaving, you have to use the satellites,” he concluded.
During the years the Landsat programme has been active, its big eye has seen changes on Earth regarding water, food, forest, urban growth and glaciers and ice. In the region, thanks to satellites NASA has observed how Saudi Arabia has drilled for water over the last 24 years. It has tapped hidden reserves of water to grow wheat and other crops in the Syrian Desert.
Other changes on Earth have to do with deforestation. From 1975 to 2012 satellites have kept record of enormous tracts of Amazonia forest vanish in Rondonia, a state in Western Brazil.
Alterations on Earth that affect food supplies, like those in the Ohio Rivers in the US, have also been recorded by satellites. These rivers spilled over their banks at the confluence of the Wabash and Ohio in early May 2011. The flood waters inundated homes, businesses, and agricultural fields.
Regarding urban growth, Landsat images reveal how certain cities have grown rapidly since 1978. An example is Tehran, in Iran, that has grown quickly since 1985, causing the loss of numerous green areas. In a way that the appearance of the city from space has changed from green to mainly grey.
Landsat has observed as well the shrinking of glaciers in Greenland, Alaska and Antarctica. Also on Puncak Jaya, Indonesia there has been a big ice loss, with two glaciers disappearing and three retreated dramatically.
Ultimately, Lansat has seen the world change in the last 40 years. Without blinking the satellite has watched the urbanization of Dubai, including the construction of hundreds of artificial islands, or the Kuwait oil fires, among other phenomena. These images are available for the world to see and reflect on how Earth is behaving as a planet and the human influence on this behavior.The Peninsula
