Thursday, 6 February 2014

Climate change; did I do it?

I was a skeptic; I didn't believe a word of it. Climate change was just the latest trend in scientific research and people in white lab coats were scrambling to get on the ‘gravy train’ before someone came along and burst the bubble.

Talk of climate change has been in the air for nearly two decades and has raised enormous concern and considerable debate in our information society. Opinion polls showed that there was a peak of support in 2008 followed by a fall in 2010. In fact opinion has moved up and down like the mercury in our thermometers.

 As the oceans warm, storms become much more violent.

According to a survey released in January, 2010 by Yale and George Mason Universities, only about 50percent of Americans were concerned about global warming, less than 50 percent thought humans contributed to it, and more than 43 percent didn’t believe it was happening at all.

In another study published by Yale University in October, 2010 only 57 percent of Americans knew what greenhouse gases are and only half knew they were produced mostly through human activity. Incredibly, 75 percent had never heard of ocean acidification or coral bleaching. It seems strange then that the general population was still in the dark.

Is it really happening?

By June, 2010 Science published the first comprehensive synthesis of climate change studies dealing with the ocean. The startling results were that the rates of change in man-made atmospheric green house gases were driving irreversible and dramatic changes in the way the ocean worked.

Prof. Hoegh-Guldberg, Director of The University of Queensland’s Global Change Institute, predicted dire impacts on hundreds of millions of people around the globe.

"Although there remains active discussion among scientists on many details about the pace and effects of climate change, no leading science organization disagrees that human activities are now changing the Earth's climate. The strong scientific agreement on this point contrasts with the partisan disagreement seen on all of our surveys," said Lawrence Hamilton, professor of sociology and senior fellow with the UNH Carsey Institute.

So what is global warming?
The greenhouse effect was discovered in 1860 by John Tyndall. Since the early 20th century, the average temperature of the Earth has increased about 0.8oC and most of this has happened since 1980. In statistical terms we are about 95 percent sure that the warming is from greenhouse gases from burning fossil fuel and cutting forests. The biggest contributors are electricity, industry, and transport (adding up to about 54 percent). This idea is now accepted by the national science organisations of all major industrialized countries.

Greenhouse gases, principally carbon dioxide, absorb heat from the sun and raise the temperature of the atmosphere and ocean. Carbon dioxide has increased by an unbelievable 24 percent in the last 50 years and from polar ice cores we know it is now higher than any time in the last 800 thousand years and probably in the last 20 million years.  Carbon dioxide is expected to reach over 900 parts per million during this century which is an incredible increase of 250 percent since we started burning fossil fuels.

The Fourth Assessment Report (AR4) by the Intergovernmental Panel on Climate Change (IPCC, 2007) indicated that during the 21st century the global surface temperature is likely to rise a further 1.1 to 2.9 °C for their lowest emissions scenario and 2.4 to 6.4 °C for their highest. Because water easily absorbs heat, 93.4 percent of global warming affects the ocean.

These may seem like tiny increases but in fact they are disastrously large. Even small changes in temperature may cause big changes in the climate. We can expect an expansion of deserts and much less rain in parts of the tropics. Melting of the ice caps will change ocean circulation and seafood production. There will be unprecedented extinctions of wildlife on a global scale.

 The impact of global warming is easily seen in these satellite photos of the Arctic.

This all sounds pretty awful but to many people it is seen as just another inconvenience. Life will go on with ‘business as usual’. Flooding of the major cities by the end of the century; I’ll be dead by then!

The problem is that an awful lot of people may be dead a lot sooner and it won’t be business as usual at all.

Where is it going to ‘hurt’ the most?

It is estimated that a global rise in temperature of only 1.5-2 °C will bring about the catastrophic extinction of many of the Earth’s species. We aren’t just talking about species we don’t ‘need’ or don’t ‘like’. In one study published in Nature in 2004, between 15 and 37% of 1103 endemic or near-endemic known plant and animal species will be "committed to extinction" by 2050. 
But climate change is only starting. Global warming will catapult the Earth and our society into entirely new situations with new rules. Even a 2 °C rise above the pre-industrial level will be outside the range of temperatures experienced by human civilization.
In the tropical seas coral reefs and their fisheries simply will not survive the temperature rise. Coral bleaching, which kills coral, occurs with rises of as little as 1 °C above the summer maximum. Without corals the food web of reefs and the populations of people who depend on them will collapse.

Coral bleaching happens when corals expel their food producing algae. Starvation is the result.

Coral reefs are already the world’s most endangered ecosystem supporting 25 percent of the ocean’s species. The collapse of these incredibly complex “islands of life” will send not a ripple but a ‘tsunami of change’ through the oceans of the world and through Coral Triangle and Pacific Island communities where some 200 million people are sustained by tropical fisheries.

The situation may be even worse in the open ocean where tiny drifting creatures like sea butterflies and planktonic animals and plants grow thin calcium shells over their fragile bodies. Even if they cope with the rising temperature, the increased carbon dioxide produces a weak acid in seawater that dissolves their shells and kills them.

The fragile sea butterfly is an important food for most of the world's fisheries.

These frail creatures exist in the trillions and are the food of all the commercial fisheries and most whales. Scientists say that most of these tiny species will be lost by 2065. Between now and then there will be huge disruptions of the ecological food web as species begin to drop out. From about 2065 on we can expect the rapid and catastrophic collapse of most commercial fisheries. The ocean ecosystem will simply fail.

In June, 2010 Science magazine we find that the oceans are now changing at a rate not seen for millions of years. "We are entering a period in which the very ocean services upon which humanity depends are undergoing massive change and in some cases beginning to fail," says Prof. Hoegh-Guldberg. "Further degradation will continue to create enormous challenges and costs for societies worldwide."

The loss of Arctic ice is now so fast that many scientists believe it can not be reversed.

What will happen to us as the earth grows warmer?

UNESCO predicts that 100-150 million people in S.E. Asia alone will be displaced through shoreline erosion, rising sea level, drought, and food shortages by 2050.

Approximately 40% of the world's agricultural land was already seriously degraded in 2007. If current trends of soil degradation continue as they are in Africa, underdeveloped countries might be able to feed just 25% of their population by 2025 (based on UNU's Ghana-based Institute for Natural Resources in Africa).

Africa, small islands, and Asian mega-deltas are regions that are likely to be badly affected. Rainfall in much of S.E. Asia will be very much less and many areas will become much drier or deserts including Indonesia, Malaysia, and Borneo.
This may seem like an inconvenience to some but to people living in agricultural and subsistence economies throughout the tropics this is bad news. The impact of global warming will be disproportionately large for disadvantaged communities where resources, food, and health are already problems (Environmental Justice, Dec. 2009).

"We are becoming increasingly certain that the world's marine ecosystems are approaching tipping points. These tipping points are where change accelerates and causes unrelated impacts on other systems, the results of which we really have no power or model to foresee."

Prof. Hoegh-Guldberg concludes: "These challenges underscore the urgency with which world leaders must act to limit further growth of greenhouse gases and thereby reduce the risk of these events occurring. Ignoring the science is not an option."

I am not alone in my belief that we are on the brink of environmental catastrophe and have been joined in my concerns by 155 senior marine scientists from 26 countries who recently signed the Monaco Declaration (The Royal Society, 6 July 2009), highlighting the twin threat of growing ocean acidification and global warming.
It took me most of my childhood to be able to admit mistakes and say “I did it”. Looking back at the way we have lived and wasted the resources of this world we have to admit it is our fault; there is no doubt; we did it. The question now is will we accept responsibility for repairing the damage. Time is running out.


If you are interested in some of the latest topics in ocean conservation check out some of the other posts on this site.

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