Chapter 2: The Climate Change Challenge

Climate change is one of the greatest global challenges of the 21st century, and increasing evidence of present and anticipated impacts of climate change highlight the need for action. The IPCC’s Third Assessment Report noted that the Earth’s average surface temperature increased 0.6 ±0.2°C in the 20th century^[1]. This trend is expected to persist, with an increase of 1.4 to 5.8°C by 2100. Even with “best case” mitigation efforts, some climate change cannot be avoided due to the inertia of the global climate system. Warming will vary by region and be accompanied by significant changes in precipitation patterns as well as changes in the frequency and intensity of some extreme events. Average global sea levels are projected to rise between nine and 88 centimeters (cm) by 2100, with implications for the 50 to 70 per cent of the world’s population currently living in low-lying coastal areas^[2]. The probability of large-scale and irreversible impacts, such as the collapse of the Greenland Ice Sheet and the slowing (or shutting down) of the Atlantic Ocean conveyor belt, is expected to increase with the rate, magnitude and duration of change^[3].

A number of climate records have been set recently, with most climatologists pointing to climate change as a significant factor:

• record temperatures were recorded in the July 2006 heat wave in Europe;^[4]
• five of the last 10 years have set records as the warmest ever (1998, 2002, 2003, 2004 and 2005). 2005 was the warmest year on record;^[5]
• there were 15 hurricanes in 2005 surpassing the previous record of 12, the most Category Five storms and the most hurricane damage ever; ^[6] and
• a record low for Arctic sea ice was recorded in June 2004—six per cent below average.^[7]

Changes in temperature and precipitation patterns have already impacted natural and human systems. Observed changes include inter alia shrinking glaciers; thawing permafrost; later freezing and earlier break-up ofice on rivers and lakes; rising sea levels; extended mid-to-high-latitude growing seasons; poleward and altitudinal shifts of plant and animal ranges; and declines of some plant and animal populations^[8]. Documented impacts also include the spread of disease vectors including malaria; the destruction of coral reefs from warmer seas and extreme weather events; and threats to low-lying island states^[9].

The provision of ecosystem goods and services will be disrupted with coast-lines and mountaintops more susceptible to irreversible losses. Projected climate change is expected to increase agricultural production in industrialized countries, while developing countries will face a decrease in agricultural land, potential cereal production and food security. More people will become water-stressed as hydrologic variability affects water quality and supply. In addition to altering biophysical systems, climate change will affect human health and socio-economic well-being. Recent increases in floods and droughts have already led to corresponding increases in damages and insurance impacts^[10]. In the future, even modest levels of warming are expected to increase the risks of hunger and disease^[11].

Although climate change impacts will affect all countries, the poor, primarily but by no means exclusively in developing countries, will be disproportionately affected. Their reliance on local ecological resources, coupled with existing stresses on health and well-being (e.g., HIV/AIDS, illiteracy) and limited financial, institutional and human resources leave the poor most vulnerable and least able to adapt to the impacts of climate change. Consequently, there is growing recognition that climate change may undermine the ability of developing countries to meet the targets put forth in the Millennium Development Goals (MDGs). Most ironically, the vast majority of those most vulnerable to the impacts of climate change are also the least responsible for contributing to it in the form of GHG emissions—whether the indigenous in Northern communities, the subsistence farmer in Sub-Saharan Africa or the small island dweller in the South Pacific.

Nor should we be oblivious to the possible opportunities that may present themselves under climate change scenarios. Changes in temperature and precipitation regimes might make it possible to grow food crops in new locations, potentially contributing to increased food security. In the Arctic regions, warmer winters and ocean waters could lengthen the summer ice-free season, creating economic opportunities for Northern communities (while simultaneously raising concerns about potential ramifications for Northern ecosystems and traditional ways of life). As the process of global warming continues, it will be important to identify, assess and take advantage of new opportunities as they emerge.

Countries are only beginning to grapple with the reality of rising GHG emissions, and a number of processes at the multilateral level offer opportunity to implement strategies to allow countries to engage in dialogue and take action on climate change. (Prominent multilateral initiatives are outlined in the Appendix.) Yet, the threat posed by climate change indicates that decisions and actions will need to go beyond environmental policy and be addressed on a number of fronts.

Notes

1. ^Intergovernmental Panel on Climate Change (IPCC), 2001.Third Assessment Report, Synthesis: Summary for Policy Makers. United Nations.
2. ^Meteorological Services Canada, 2002. Frequently Asked Questions about the Science of Climate Change.
3. ^A study by the Southampton Oceanography Centre and the Tyndall Centre for Climate Change Research focused on improving estimates of the probable collapse of the thermohaline circulation system. Preliminary results suggest that the probability of this event happening is 10 times higher than originally predicted. See Challenor, P., R. Hankin and B. Marsh. 2005. “The Probability of Rapid Climate Change,” a presentation made at conference: Avoiding Dangerous Climate Change, February 1–3, 2005, Exeter, U.K.
4. ^Godoy, Julio. 2006. Global Warming, Not Just Heat Wave. Inter Press Service, July 21, 2006.
5. ^NASA Goddard Institute for Space Studies Surface Temperature Analysis, 2006. Global Temperature Trends: 2005 Summation.
6. ^National Oceanic and Atmospheric Administration, 2006. NOAA Reviews Record-Setting 2005 Atlantic Hurricane Season: Active Hurricane Era Likely To Continue.
7. ^NASA Earth Observatory, 2006. Record Low for June Arctic Sea Ice.
8. ^IPCC. 2001. Third Assessment Report, Synthesis: Summary for Policy Makers. Intergovernmental Panel on Climate Change, United Nations; and Arctic Climate Impact Assessment, 2004. Impacts of a Warming Climate. Cambridge, U.K.: Cambridge University Press.
9. ^Levin, Kelly and Jonathan Pershing. 2006. Issue Brief: Climate Science 2005: Major New Discoveries. Washington, D.C.: World Resources Institute.
10. ^IPCC. 2001. Third Assessment Report, Synthesis: Summary for Policy Makers. Intergovernmental Panel on Climate Change, United Nations; and Arctic Climate Impact Assessment, 2004. Impacts of a Warming Climate. Cambridge, U.K.: Cambridge University Press.
11. ^Parry et al., predict that even at modest levels of global warming, by 2080, tens of millions of people worldwide will be put at additional risk of experiencing hunger and coastal flooding, hundreds of millions at risk of experiencing malaria, and billions of people at risk of experiencing water shortages. See Parry, Martin, Nigel Arnell, Tony McMichael, Robert Nicholls, Pim Martens, Sari Kovats, Matthew Livermore, Cynthia Rosenzweig, Ana Iglesias and Gunther Fischer, 2001. “Millions at Risk: Defining critical climate change threats and targets,” Global Environmental Change, (11): 181–183.