Monday, 30 September 2013 00:37
The obvious has been said. Humans are the main cause of global warming. In fact 95% of the fault is with humans and the news is bad – very bad. Leading climate scientists said on Friday they were more certain than ever before that mankind was the main culprit for global warming and warned the impact of greenhouse gas emissions would linger for centuries.
A report by the Intergovernmental Panel on Climate Change (IPCC) played down the fact temperatures have risen more slowly in the past 15 years, saying there were substantial natural variations that masked a long-term warming trend. It said the Earth was set for further warming and more heat waves, floods, droughts and rising sea levels as greenhouse gases built up in the atmosphere. The oceans would become more acidic in a threat to some marine life.
Another alarming point the Reuters report made was that temperatures were likely to rise by between 0.3 and 4.8 degrees Celsius (0.5 to 8.6 Fahrenheit) by the late 21st century. The low end of the range would only be achieved if governments sharply cut greenhouse gas emissions. And it said world sea levels could rise by between 26 and 82 cm (10 to 32 inches) by the late 21st century, driven up by melting ice and an expansion of water as it warms, in a threat to coastal cities from Shanghai to San Francisco.
The IPCC report also presents some hard choices for humans to make, including the critical point that humans will have to keep the vast majority of their fossil-fuel reserves in the ground if they want to keep global warming below 2 degrees Celsius, the level deemed “dangerous” by world leaders.
Bringing more bad news to the world’s energy crisis the report insists that only one sixth of fossil fuel reserves can be used if the climate is to be kept below two degrees. The math is pretty straightforward: Humans have already emitted about 531 billion tons of carbon since the Industrial Revolution, by clearing forests and burning fossil fuels. And, scientists calculate, humans can only emit another 469 billion tons or so if they want a good shot at keeping global warming below two degrees.
The world is currently on pace to do that by 2040. However, even if carbon emissions stop tomorrow, sea levels will keep rising. But the population can make the difference between a moderate rise of sea level versus a massive rise that could wipe out small island nations.
In recent years, some scientists have despaired of the idea that humans will ever cut their greenhouse-gas emissions and have looked to ‘geoengineering’ schemes that could artificially cool the planet. The IPCC, however, thinks that this idea does carry some risks, like mucking with global patterns of rainfall so only the hard road is recommended.
Sadly, Sri Lanka, which is blessed by nature, is being bled out by, some would argue, outdated policies such as coal power plants, large dams and unsustainable agriculture practices. The latter in particular has been dire, with rice farming in particular using up excessive amounts of water. Protecting biodiversity through forest, marine and other conservation is essential but these are largely ignored by officials and starved of funding. Could this be the final wakeup call?