|
|
|
|
|
Global warming (GW) is treacherous in many ways and depending where you live on the planet it basically can:
Global warming is altering the distribution and abundance of plant and animal species. Application of a basic law of ecology predicts that many will vanish if temperatures continue to rise. How great is that threat to biodiversity?
It is projected that by year 2050, the extinction probabilities for a sample of 1,103 species representing terrestrial regions from Mexico to Australia would sharply increase. If temperatures follow middle-of-the-road projections, about one-quarter of these species may disappear, a lossexceeding that expected from habitat destruction. (reference)
In the model used to make such predictions, it is assumed that each species can persist only under a particular set of climatic conditions. This 'climate envelope', assessed by modeling current geographical distribution in relation to climatic gradients, serves to predict future distribution. As warming alters these gradients, many species are shifting towards the poles or to higher elevations, their ranges often contracting as the area of climatically suitable habitat declines.
The effects of rising temperatures and other changes could magnify the impact of global warming. In the highlands, for example, an increase in the altitudes at which clouds form could affect communities that require frequent immersion in clouds and mist.
Changes in cloud cover might also be important. Warming accelerates evaporation and increases the air capacity to hold water, thereby increasing its content of water vapor. Cloud formation, however, depends on relative humidity, which varies inversely with temperature, so warming may reduce cloudiness over some regions. In contrast, where air masses cool sufficiently, where they ascend mountain slopes for example, increased water vapor translates into enhanced cloud formation, even if condensation begins at increased altitudes. Accordingly, widespread increases in cloud cover are under way.
Are changing cloud patterns already contributing to the extinction of species? The amphibian decline and disappearance in the mountains of Costa Rica are one example in which recent warming has been implicated in such losses. Various biological changes in these mountains are associated with unusually dry weather attributed to an increase in heights of cloud formation. Understanding amphibian extinctions is crucial, given that they are taking place in highlands around the world.
Both increased cloud cover and unusually dry weather might hamper the survival ability of these amphibians. Under clear skies, temperatures in these highlands can quickly exceed 30°C, so an amphibian can 'escape' from this envelope. Under cloudy skies, however, microhabitat temperatures mirror ambient temperatures, making escape difficult. Dry conditions may have similar consequences: with limiting moisture, an amphibian might have to stay in cool, damp places.
Although coroners will not write it officially on a death certificate, GW scientists predict global warming will be the ultimate cause of death as people succumb to disease in an increasingly unhealthy environment. Global warming has a nasty tendency to create a favorable climate for disease-causing organisms and food-plant pests. While the evidence of significant global climate changes is minimal, there are already noticeable increases in human diseases worldwide. (reference)
Diseases that breed in warm and wet conditions were likely to become more prevalent in the next 20 years. The potential for disease epidemics such as malaria, Dengue fever, diarrhea and food poisoning is also likely to rise dramatically.
You want to share some ideas, or data with the visitors of the Corrosion Doctors Web siteplease send a note to our
