Just People The population of the world we live in grows every eight seconds Earth has more than 7 2 billion people living on it The United States is the third most populated country in the world behind China and India Population affects the planet in many ways Much of the world’s air water and land are facing a global crisis China is the most densely populated country with nearly 1 4 billion people China 4
The challenge is to create and maintain an effective sustainable way of living that involves preventing global warming and climate change clean air and water the management of natural and manmade resources to avoid waste and protecting energy supplies and all living things Many branches of science involve people and the planet Broadly they all fall under the category of natural science 5
Through remote sensing Aura spacecraft instruments measure trace gases in the atmosphere Launched on July 15th 2004 it studies chemical interactions and climate change in the Earth’s atmosphere Earth-orbiting satellites and technological advances allow scientists to collect data about Earth and its systems Much of this data concludes that our planet’s climate is changing 6 Evidence of Climate Change Global sea levels are rising Global temperatures are rising Oceans are warming Ice sheets are thinning and shrinking Glaciers are retreating Precipitation is more intense Ocean water is more acidic Snow in the Northern Hemisphere is melting earlier
NASA has more than a dozen Earth science spacecraft instruments in orbit studying all aspects of Earth's systems oceans land atmosphere biosphere cryosphere State of the art research on climate science enables the international scientific community to advance science using space-based observations The average temperature in a year is the critical factor for permafrost existence Permafrost temperatures at 3 3 feet 1 meter below ground in central Alaska have warmed since the 1960s Soil and rock that is frozen all year round is called permafrost It’s found in Alaska Canada and other northern countries While most of the ground is frozen plants still grow in the soil at the surface 7
