I am no expert on global warming, climate change, or environmental science, so I have rely on the convergence of wisdom from scientists who really know this stuff. Some paint apocalyptic-like scenarios, while others simply see an emerging crisis, but nearly all who study the subject seriously agree that things are getting worse rather than better.
Having admitted to not being an environmental scientist - or even to playing one on TV - I'll share my super-simple understanding of the basic problem, then speculate a bit about how it might affect global security.
Global Warming 101:
As the earth's temperature persistently rises, a cascade of effects necessarily results.
The absolute amount of temperature increase we're talking about is not huge, but the consequences can be. So far, the earth's temperature has only risen .8 of one degree (Celsius), but it's still creeping upward. Most scientists estimate a 2 degree (Celsius) temperature increase to be the critical tipping point for cataclysmic effects.
Greenhouse gas emissions increase the amount of carbon dioxide in the atmosphere. US and China, by the way, are the world leaders in greenhouse gas emissions.
Increases in atmospheric carbon dioxide levels are a major contributor to the warming trend. More atmospheric carbon dioxide elevates the earth's temperature.
When atmospheric carbon dioxide hits 450 parts per million - or maybe even before then - it will cause the earth's temperature to increase those catastrophic 2 degrees.
The levels now are around 385 parts per million and rising. Point is - at this rate we're not that far off. Almost certainly within your lifetime.
Effects and Conditions:
Already we are seeing some pretty profound effects.
The warming trend is even changing geography, for example, by causing the destruction of the 25-mile ice bridge that used to link the Wilkins ice shelf to the Antarctic continent.
At the other end of the earth, ice is melting in Greenland, causing river levels to rise dramatically. As the ocean levels rise to the North and the South, of course, they rise in the middle also, even potentially threatening the East Coast of the US, particularly coastal areas, where a substantial proportion of the American populations currently lives.
Some countries particularly in China and volatile regions of South Asia, rely on massive glaciers, like those in the Himalayas, as a water source. As the glaciers melt, their water supply is endangered. Incidentally, most of the Arab world also gets its water supplies from beyond its borders.
On the other hand, rising temperatures also expand areas of desert-like non arable land and reduce rainfall. That's a real problem in a bunch of areas in sub-Saharan Africa, potentially prompting forced migration and new conflicts over land, water access, and agricultural industry.
Climate change is projected to substantially affect water and food supplies, extreme weather/natural disasters, and health/disease.
Implications for Security:
A 2007 study by the Center for Naval Analyses Corporation titled National Security and the Threat of Climate Change, addresses a number of specific scenarios and mechanisms by which the effects of climate change may act as force multipliers, disproportionately affecting conditions in the most vulnerable places- fragile, weak and failing states - exacerbating their instability.
In the national and international security environment, climate change threatens to add new hostile and stressing factors. On the simplest level, it has the potential to create sustained natural and humanitarian disasters on a scale far beyond those we see today. The consequences will likely foster political instability where societal demands exceed the capacity of governments to cope.
Defense Secretary Robert Gates has recognized the implications of climate change for our Nation's defense and security, and his warning resonates with the June 2008 assessment of the Intelligence Community in The National Security Implications of Global Climate Change Through 2030 that:
From a national security perspective, climate change has the potential to affect lives (for example, through food and water shortages, increased health problems including the spread of disease, and increased potential for conflict), property (for example through ground subsidence, flooding, coastal erosion, and extreme weather events), and other security interests..... Climate change could affect domestic stability in a number of key states, the opening of new sea lanes and access to raw materials, and the global economy more broadly—with significant geopolitical consequences.
The estimates notes specifically:
- Climate-induced tensions are a main contributor to instability in several areas of Africa.
- South, Southeast, and East Asia will face risks of reduced agricultural productivity as large parts of the region face increased risk of floods and droughts.
- Economic refugees will perceive additional reasons to flee their homes because of harsher climates. Many likely receiving nations will have neither the resources nor interest to host these climate migrants.
- As climate changes spur more humanitarian emergencies, the international community’s capacity to respond will be increasingly strained.