Fragmento

In the debate about global warming we forget at our peril the role of ecosystems in giving us a climate we can live with. Life co-evolving with our planet over thousands of millions of years has created an environment apt for millions upon millions of species, from bacteria to the massive whale or towering redwood trees. In its totality and working together through complex, even endogenous, symbiotic relationships, life gives us a relatively stable climate, modifying the amount of heat stored at the Earth’s surface, regulating the clouds that bring rain to the continents, and changing the colour of the Earth so that it differentially absorbs energy from the Sun or on the contrary, reflects it back into space. The warming effect of a darker colour can therefore thwart our efforts to reduce the impact of anthropogenic increases in the atmospheric concentrations of greenhouse gases. One consequence of global warming is that the boreal forest is spreading, absorbing CO₂ in its growth, and, in principle, helping to cool the planet. However, fir trees, by dint of their pyramidical shape, shed snow from their branches, so exposing dark green needles to the first rays of the Spring sunshine. The overall effect of that spurt in growth is, therefore, to warm the planet rather than cool it. Gaia is always in the process of becoming, step by step modifying conditions at the Earth’s surface, and, as James Lovelock has so vividly described, bringing about temperature regulation as an emergent property of the intertwined system of life and its local environment. How inadequate, therefore, the great majority of climate models, which on account of the difficulty of putting precise numbers to life’s role in generating climate, take the easy way out and leave life out of the equation.

Palabras clave: .

2008-12-09   |   791 visitas   |   Evalua este artículo 0 valoraciones

Vol. 12 Núm.1. Enero-Junio 2008 Pags. 11-14. Rev Orinoquia 2008; 12(1)