EXTREME WEATHER

A warmer climate provides fuel for all kinds of weather on a much larger scale. Everything from increased rainfall to droughts to cyclones will become awfully familiar. Where? When? How?

HURRICANES

Warmer ocean temperatures colliding with our increasingly warm, moist atmosphere creates a breeding ground that fuels tropical storms. Hurricanes in the Atlantic and Pacific oceans have intensified by 50% since the 1970s, in both wind speed and duration. The past few years have witnessed the emergence of a new kind of hurricane—they’re getting stronger, wetter and much more powerful.

In 2004, the state of Florida was visited by four large hurricanes while Japan was hit by a record-breaking 10 typhoons. That same year the United States experienced the most tornado activity ever recorded. The summer of 2005 saw Hurricane Katrina devastate New Orleans while Australia was hit by several category-5 hurricanes.^1,2

SERIOUS DOWNPOURS

Just because you don’t live in the tropics or on the coast, that's no reason to feel secure. Annual precipitation is expected to increase in the 21st century, to the tune of 1% for every degree of global warming. It goes without saying that more rain, and heavier rain, creates problems that range from the small to the stupendous.

Heavy, frequent rains run off the ground, rather than becoming absorbed into the soil. This means nutrient-rich topsoil washes away into sewers, rivers and other bodies of water. In the case of major weather events—hurricanes, tornadoes and thunderstorms—anything can happen. Crops drown, power lines are downed, and bridges and roads can be swept away. Severe flooding occurs. Disrupted slabs of earth can cause landslides. And then, in warmer climates, the shallow, stagnant pools of water left after a storm become breeding grounds for mosquitoes and other disease-carrying species.

HEAT WAVES

An increase in our average temperature by just one or two degrees will make our hottest summer scorchers even more scorching. For all those people without air conditioning, the heat could become unbearable—think of the elderly, and people who are sick. In fact, just think of the majority of the earth’s population, for whom air conditioning is an unimaginable luxury. Large, densely populated cities are often hit hardest by heat waves, because the asphalt, concrete and glass act as insulators that trap the heat and keep it from escaping. This trapped heat also releases allergens. People with asthma and respiratory ailments are at great risk during heat waves. In the summer of 2003, Europe was hit with a devastating heat wave. Temperatures soared over 40 degrees in some places, causing 30,000 heat-related deaths.

DROUGHT

Some parts of the planet are more prone to drought than others. But global warming will lengthen and intensify those droughts, and worsen the fallout: food and water shortages, displacement, disease… you get the idea. Even if rainfall patterns remain unchanged, higher temperatures will still cause moisture to evaporate more quickly from the soil, meaning less time for plants to soak up nutrients.

Growing seasons are also affected by warmer, shorter winters. If snow accumulation starts to drop, the spring run-off decreases in volume, and lakes and rivers cannot be replenished. Irrigation becomes much more difficult, and we face similar problems: depleted crops, economic repercusions… you still get the idea.

Droughts make plants and trees more vulnerable to infestations: Warmer winters in British Columbia have exacerbated the spread of the mountain pine beetle. Their infestation will destroy 80% of BC’s lodgepole pine by 2020.³ On the prairies, grasshopper and spider populations can flourish in warm, dry weather, wreaking havoc on wheat and soybean crops.

During droughts, our forests become especially vulnerable to fire. The summer of 2003 saw vast stretches of BC’s interior and mixed forests burning. Almost 2,500 fires raged that summer,⁴ fuelled by a four-year drought, destroying the habitat of animals and the property and livelihood of humans. If that weren’t bad enough, massive forest fires directly affect the levels of carbon dioxide in our atmosphere: as forests burn, the ability to store carbon goes with them, and the carbon they had stored is released once again into the atmosphere.

^{1 Source: http://www.pewclimate.org/hurricanes.cfm}
^{2 Source: Gore, Al. An Inconvenient Truth. Emmaus: Rodale, 2006. 80-82.}
^{3 Source: http://cfs.nrcan.gc.ca/sof/sof06/InFocus02_e.html}
^{4 Source: http://www.wildernesscommittee.org/campaigns/policy/forest_fires}