To Canadians who live through long, cold winters, an increase in the average global temperature might not sound like such a bad thing. However, scientists say global warming is having an impact on weather patterns around the world. It's showing up in shifts in seasons, rising sea levels, and catastrophic weather events like drought and flooding.

Scientists recently mapped out the countries most likely to be affected by climate change. They include some of the poorest and least industrialized parts of the world.

In other words, those who have contributed the least to global warming—and who are least able to deal with its effects—are the ones who will suffer most.

Food Security
Changes to seasonal weather patterns means that the crops and planting methods farmers have depended on for generations are failing.

More droughts and flooding also mean that more people, who were once able to feed themselves, go hungry. The United Nations says one in six countries already faces food shortages due to droughts that could become semi-permanent because of climate change.

Global warming is also drying up farmland. By 2008, the World Food Programme predicts the amount of arid land in Africa will increase by 90 million hectares—an area almost four times the size of Great Britain.

Fresh Water
Drought has a devastating effect on water supply, but so does rising sea levels. In Bangladesh, aid workers say sea water is seeping into wells, making the water unfit for drinking and irrigation.

Scientists are also concerned about people who depend on water from glaciers and melting snow in places like the Andes and the Himalayas. They believe rising global temperatures could lead to severe water shortages for up to a sixth of the world's population.

Disease
Global warming creates prime conditions for many infectious and mosquito-borne diseases. The parasite that spreads malaria, for example, develops more quickly in warmer temperatures.

A study done in Peru has linked an exponential increase in hospital admissions for children with diarrhea, to heat waves caused by the El Niño—a weather phenomenon some attribute to global warming.

These kinds of problems have led the World Health Organization to attribute five million extra illnesses and 150,000 extra deaths each year to disease and malnutrition caused by climate change.

The Poor are More Vulnerable
The catastrophic weather events associated with global warming have a bigger impact on the poor, because they often live in places that lack the long-term planning and engineering that could protect their homes and crops.

They also lack the resources to replant and rebuild when disaster strikes and are less likely to have access to medical care to treat or prevent diseases.

What World Vision is Doing to Help
Click here to read what World Vision environmentalist Doug Brown has to say about global warming and its impact on World Vision's work.