File:Impacts of global warming 2.png

Summary

This diagram shows some of the main impacts of global warming. This is a draft image for discussion on <a href="https://en.wikipedia.org/wiki/Talk:Effects_of_global_warming" class="extiw" title="en:Talk:Effects of global warming">Talk:Effects of global warming</a>. Impacts are organized into 4 categories: (1) Physical systems, (2) <a href="https://en.wikipedia.org/wiki/ecological_systems" class="extiw" title="en:ecological systems">ecological systems</a>, (3) <a href="https://en.wikipedia.org/wiki/social_systems" class="extiw" title="en:social systems">social systems</a>; and (4) abrupt and large-scale changes. The shaded bars indicate the level of risk associated with different magnitudes of <a href="https://en.wikipedia.org/wiki/global_warming" class="extiw" title="en:global warming">global warming</a>. The following scale is used:

• White shading: no detectable risk
• Light grey: small risk
• Medium grey: moderate risk
• Dark grey: large risk
• Black: severe risk

Risks apply to observed and projected <a href="https://en.wikipedia.org/wiki/climate_change" class="extiw" title="en:climate change">climate change</a>. Later text explains whether observed risks are attributable to climate change or due to climate variability. Some risks are given based on (1) current <a href="https://en.wikipedia.org/wiki/Adaptation_to_global_warming" class="extiw" title="en:Adaptation to global warming">adaptation</a> (c.a.) practices to climate variability and change, and (2) for a <a href="https://en.wikipedia.org/wiki/hypothesized" class="extiw" title="en:hypothesized">hypothesized</a> highly adapted state (h.a.). Global temperatures are measured relative to pre-<a href="https://en.wikipedia.org/wiki/Industrial_Revolution" class="extiw" title="en:Industrial Revolution">industrial</a> times, approximated as the years 1850 to 1900. Recent times are taken as 2003 to 2012.

Physical systems

• Increase in risk associated with some extreme weather events: small to moderate risk at present; large risk starting around 1.6 <a href="https://en.wikipedia.org/wiki/%C2%B0C" class="extiw" title="en:°C">°C</a>.
• Other <a href="https://en.wikipedia.org/wiki/effects_of_global_warming" class="extiw" title="en:effects of global warming">effects of global warming</a> include global <a href="https://en.wikipedia.org/wiki/mean" class="extiw" title="en:mean">mean</a> sea level rise and <a href="https://en.wikipedia.org/wiki/ocean_acidification" class="extiw" title="en:ocean acidification">ocean acidification</a>. Global warming could be irreversible for several millennia.

Ecological systems

• Climate change is a significant risk for some <a href="https://en.wikipedia.org/wiki/ecosystems" class="extiw" title="en:ecosystems">ecosystems</a> and organisms, e.g., Arctic ecosystems and coral reefs: Moderate risk at present; large risk from 1.6 °C; severe risk from 2.6 °C.
• Risk of widespread extinctions: Small at present; moderate at 2 °C; large at 4 °C.

Social systems

• Sectors affected include food security, water resources and human <a href="https://en.wikipedia.org/wiki/health" class="extiw" title="en:health">health</a>. Impacts will be uneven within and across different countries. Climate change increases the risk of many negative impacts, but there will be some positive effects.
• Africa: Risks associated with reduced <a href="https://en.wikipedia.org/wiki/crop_productivity" class="extiw" title="en:crop productivity">crop productivity</a>: Present: Moderate (c.a.) or low (h.a.) risk from climate variability; 2 °C: high (c.a.) or moderate (h.a); 4 °C: very high (c.a. and h.a.)
• North America: Risks associated with urban flooding in <a href="https://en.wikipedia.org/wiki/River" class="extiw" title="en:River">riverine</a> and coastal areas: Present: Moderate (c.a.) or low (h.a.) risk from climate variability; 2 °C: moderate (c.a. and h.a); 4 °C: high (c.a. and h.a.).

Abrupt and large-scale changes

Climate change can lead to abrupt and large-scale changes in natural and human systems. The risk of these changes increases with temperature.

• Declines in late-summer Arctic sea ice extent: Present: low to moderate risk; 2 °C moderate to large risk; 4 °C: severe risk.
• Sustained global warming could lead to the near-complete loss of the Greenland ice sheet over a millennium or more, which would result in global mean sea level rise of about 7 m: risk is low at 1 to 2 °C; moderate at 3 °C, and large at 4 °C and above.

Notes

Sources are: Working Group's I and II (WG1 and 2) contributions to the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5, 2013 and 2014); and the US National Research Council (US NRC, 2013) report "Abrupt Impacts of Climate Change: Anticipating Surprises". Details:

• IPCC AR5 WG1 references <a rel="nofollow" class="external autonumber" href="http://www.ipcc.ch/report/ar5/wg1/">[1]</a> (<a rel="nofollow" class="external text" href="https://web.archive.org/web/20140922183922/http://www.ipcc.ch/report/ar5/wg1/">archive url</a>): Summary for Policymakers
• IPCC AR5 WG2 references <a rel="nofollow" class="external autonumber" href="http://www.ipcc.ch/report/ar5/wg2/">[2]</a> (<a rel="nofollow" class="external text" href="https://web.archive.org/web/20140930030331/http://ipcc.ch/report/ar5/wg2/">archive url</a>): Summary for Policymakers; Technical Summary; Chapter 19.
• US NRC <a rel="nofollow" class="external autonumber" href="http://www.nap.edu/openbook.php?record_id=18373">[3]</a> (<a rel="nofollow" class="external text" href="https://web.archive.org/web/20140701105615/http://www.nap.edu/openbook.php?record_id=18373">archive url</a>)

Licensing

Lua error in package.lua at line 80: module 'strict' not found.