BITTER FACTS!!!

Events that foreshadow the types of impacts likely to become more frequent and widespread with continued warming: Harbingers.

Spreading disease

Warmer temperatures allow mosquitoes that transmit diseases such as malaria and dengue fever to extend their ranges and increase both their biting rate and their ability to infect humans. The map highlights locations of mosquito-borne disease outbreaks in previously unexposed highland communities where temperatures have risen during the past century, and other indicators of health impacts.

Earlier spring arrival

Spring now arrives earlier in many parts of the world. Evidence of this comes from earlier thaw dates for rivers and lakes; earlier dates for plant blooming and leafing; and earlier animal egg-laying, spawning and migration. An earlier spring may disrupt animal migrations, alter competitive balances among species, and cause other unforeseen problems.

Plant and animal range shifts and population changes

Plants and animals generally react to consistently warmer temperatures by moving to higher latitudes and elevations. Recent studies reveal that some species have already started to shift their ranges, consistent with warming trends. Many populations and species may become more vulnerable to declining numbers or extinction if warming occurs faster than they can respond or if human development presents barriers to their migration.

Coral reef bleaching

Reefs in 32 countries experienced dramatic bleaching in 1997-98. Bleaching results from the loss of microscopic algae that both color and nourish living corals. Water that is warmer than normal by only 2 to 3?F (1.1-1.6?C) has been linked to bleaching. Other factors that contribute to coral reef bleaching include nutrient and sediment runoff, pollution, coastal development, dynamiting of reefs, and natural storm damage.