NASA Global Climate Change: Vital Signs of the Planet

NASA Global Climate Change: Vital Signs of the Planet
Link	http://climate.nasa.gov/
Climate Change	Yes
Human Cause	Yes
Author(s)	NASA
Affiliation	NASA
Sponsors	NASA
Date	2012/04/22

Introduction

Organization Position Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"

Description

The Earth's climate has changed throughout history. Just in the last 650,000 years there have been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth’s orbit that change the amount of solar energy our planet receives.The current warming trend is of particular significance because most of it is very likely human-induced and proceeding at a rate that is unprecedented in the past 1,300 years.Earth-orbiting satellites and other technological advances have enabled scientists to see the big picture, collecting many different types of information about our planet and its climate on a global scale. Studying these climate data collected over many years reveal the signals of a changing climate.