Extreme Weather

Standard Page - 2006-01-06
There is strong evidence that extreme weather events – such as hurricanes, floods, droughts and heat waves – are increasing because of climate change. And while it is difficult to blame any single weather event on climate change, scientists agree that climate change brings more extreme weather events with it.

There is strong evidence that extreme weather events – such as hurricanes, floods, droughts and heat waves – are increasing because of climate change. And while it is difficult to blame any single weather event on climate change, scientists agree that climate change brings more extreme weather events with it.

In very broad terms, this is because climate change is putting more energy (heat) into the world's weather systems. This energy speeds up the whole system, increasing the number and intensity of storms.

 

Flooding in Guangdong14 August 2007 - Record-breaking rains have flooded Leizhou, Guangdong province, due to tropical typhoon Pabuk. This man in Egan village is moving his television set.

Here are some of the weather impacts of climate change:

Heat waves

Models show that climate change could cause thousands more heat-related deaths in many major cities in the coming decades, independent of population growth. Heat waves can also harm crops, livestock, fish populations and wildlife.

The European heat wave of 2003 killed 14,800 people in France alone and more than 30,000 across the continent. According to the French National Institute of Health, the death rate was 60% higher than normal for that time of year. It was by far the worst heat wave on record.

Increased rain and flooding

Warm air can hold more water than cool air. Thus, as the atmosphere warms, it can hold more and more water vapour.

This will very likely dry up some areas, dramatically increase precipitation in others, and cause more volatile weather systems in general. The increased precipitation will cause more flooding, flash floods, landslides, erosion, crop damage, and strain on dams.

Just one example: In summer 2004, two-thirds of Bangladesh, along with much of Assam and Bihar in India, was under water. Over 50 million people were affected, with tens of thousands suffering from diarrhea as sewage mingled with the flood waters. The main monsoon rice crop was also severely damaged, forcing perhaps 20 million people to seek aid. A similar devastating flood occurred only six years ago, in 1998.

Droughts

1 January 2005 - A fishpond in the midst of a long-term drought, in Guangdong province

Climate change will likely cause dry areas to become drier. In general, there is likely to be an increase in the risk of drought in the mid-latitudes interiors of continents. The increase in droughts will hurt rich and poor nations alike, but regions that are already experiencing food and water shortages will be the harder hit.

Hurricanes

Climate change will likely not only increase the frequency of hurricanes, but also their severity.

Hurricanes need seawater temperatures above 27°C (81°F) in order to form. Water at this temperature allows for massive evaporation, which can then condense and form the storm's "vortex". As the seawater temperature goes even higher, the likelihood of storms increases exponentially.

Although there are other complex factors involved in hurricane formation, the link between warmer seawater and hurricanes is well established. It is also certain that climate change is raising ocean temperatures. Therefore, climate change is making the conditions under which hurricanes, cyclones and tropical storms form more common.

Extreme weather events in China

China has been historically prone to extreme weather events, especially when it comes to floods along the country's two main rivers, the Yangtze and the Yellow Rivers.

Climate change is already impacting the distribution of China's water resources. In the last few decades, rivers in the north – including the Yellow, Huai, Hai and Liao rivers – have had a significant reduction in water levels, while rivers in southern China have experienced a gain in water resources. Floods have become more frequent, while droughts are becoming more severe, and extreme weather events are increasing overall.

Learn more about:

Glacier Retreat in the Third Pole
Health, Food and Water
Sea Level Rise
Habitat Loss and Species Extinction

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