Change of climate that is attributed directly or indirectly to human activity, altering the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.
Removing plant life from the Earth increases CO2 concentration in the atmosphere. However, a moral distinction exists between practices that increase CO2 concentrations, but are sustainable (top photo), and practices that are unsustainable (bottom photo). [fn][[nid:1095]][/fn]
Figure 18: Time series of late summer tropical Atlantic sea surface temperature (blue) and the Power Dissipation Index (green), a measure of hurricane activity which depends on the frequency, duration, and intensity of hurricanes over a season. [fn][[nid:1092]][/fn]
Figure 16: These photographs show the retreat of Peru’s Pastoruri Glacier between 2001 and 2009. Today, what little remains of the Pastoruri is no longer technically a glacier because it does not build up ice in the winter to release in the summer. [fn][[nid:1090]][/fn]
Pastoruri Glacier [cite]
Photo courtesy Daltonic Films, from the film "Glacial Balance"
Figure 22: This series of photographs show tiny young clams dissolving in acidified water. CO2 is absorbed from the air by ocean water, acidifying the water and thus reducing the ability of juvenile clams to grow their shells. As seen in the photos, where CO2 levels rise progressively from left to right, 36-day-old clams (measured in microns) grown under elevated CO2 levels are smaller than those grown under lower CO2 levels. [fn][[nid:1088]][/fn]
earth's atmosphere figure [cite]
a. By Surachit CC BY-SA 3.0, via Wikimedia Commons b. By NASA Earth Observatory [Public domain], via Wikimedia Commons