Answer to Question 1
The Intergovernmental Panel on Climate Change (IPCC) was formed in 1988 in a joint effort of the United Nations Environmental Programme and the World Meteorological Organization and began with more than 200 scientists studying human impact on the world's climate. Over 600 scientists in 40 countries contributed to the 2007 report. To date the IPCC has issued four reports on global climate change detailing growing scientific evidence that human activities are significantly impacting the world's climate. The fifth installment from the IPCC was released in 2014.
Answer to Question 2
Scientists collect data about paleoclimate from a variety of sources. Air bubbles trapped in polar continental ice sheets can be used to date the ice layer and estimate global temperature. Similarly, land-based ice, such as mountain glaciers, provides additional paleoclimate data. Growth rings in ancient trees also yield information about past climate. Ocean sediment analyses provide additional data about past climatic variation.
Boreal forest geography and climate.
Two modes of evolutionary change.
What are examples of ideal forms?
Climate change exerts societal impacts and vice versa
Coral growth rings as an indicator of environmental change
Role of Productivity in Determining Growth, 1975–2009