Ibex in Dana Biosphere Reserve in Jordan
Nature is formed by all ecosystems on earth. Ecosystems form the backbone of the earth’s ability to provide habitable conditions. They consist of webs of plants, animals, insect and bacteria that interact with each other to create a living system. Apart from providing invaluable services to the economy, the ecosystem of the world captures large amounts of CO2 from the atmosphere and reduce the amount that stay in it (they are ‘net sinks’ of CO2). Ecosystems are under stress already; over the past 50 years, humans have changed ecosystems more rapidly and extensively than in any comparable period in human history. That led to a sizeable and irreversible loss in the biodiversity on earth. Climate change impacts are going to add on this.
Juniper forest die back
Ecosystems are very adapted to climatic conditions. They are optimized to the climate that had taken place for the last thousands of years. Slow changes, i.e. changes over periods of thousands of years, can usually be contained by natural ecosystem adaptation. Rapid changes as we are facing now…, i.e. where we see significant changes over a period of 100 years or so, are too fast for many species to adapt to. Within this century ecosystems will see the highest CO2 concentrations in at least 800 000 years, the highest temperatures in at least the last 740 000 years and the most acid ocean waters in more than 20 million years. Natural adaptation is further susceptible by man-made and natural obstacles for migration (i.e. refuge) of animals and plants.
The last time the earth experienced warming at anything like the pace we now expect was during the Paleocene-Eocene Thermal Maximum, about 55 million years ago, when temperatures rose by about 6 C° over the course of around 20,000 years (which is a much slower rate than the current pace of warming). That increase was associated with mass extinctions, which, to put it mildly, probably would not be good for living standards.
The threats from climate change do not only come in the form of higher temperatures, heat waves, and changes in precipitation. Wildfires as a result of drought, explosions in insect numbers as a result of changing climate, and more acid ocean water as a result of CO2 dissolving in sea water, all contribute to the impacts on ecosystems. Impacts on ecosystems are generally of the ‘threshold’ type, that above a certain level of temperature, acidity or drought one or more species can no longer survive (which can easily lead to extinction for species that are unique to certain areas) and with the decline in those species ecosystems as a whole may collapse.
On the other hand, the collapses in ecosystem functioning as a result of effects other than climate change (human development, desertification, land degradation and environmental pollution), cause superior effects of climate change itself; loosing ‘net sinks’ of CO2 increases CO2 concentration in the atmosphere, i.e. pollution in the sea kills microorganisms that uses CO2 in photosynthesis. That’s why; it will be wise to say “Saving ecosystems … Saving ourselves”.
By: Hussien Al-Kisswani
Climate Leader
Climate Reality project
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