Global warming & Earth’s future .
Scientists warn that global warming is all too real – but opinion is divided on our chances of long-term survival
IMAGINE a world where all that remains of Cape Town is the famous flat top of Table Mountain sticking out of the sea while the rest of the city lies submerged, shrouded in myth like the lost city of Atlantis. This may seem like the plot of a farfetched sci-fi movie, but as Earth’s ice caps keep melting and sea levels continue to rise we have to ask ourselves: can we really bury our heads in the sand like America’s president Donald Trump and say climate change is a hoax?
New figures released by analysts at Nasa and America’s National Oceanic and Atmospheric Administration (NOAA) reveal that 2016 was officially the warmest year ever documented. Average global temperatures are now almost a full degree warmer than they were in the mid-20th century – and scientists are worried.
“In 2014, 2015 and 2016 we have had the three hottest years on record. Scientists call it a ‘three-peat’. It’s very rare and also worrying that 2015 and 2016 were both a lot warmer than the long-term global average,” says Professor Guy Midgley, an expert in biodiversity and global change science at the department of botany and zoology at Stellenbosch University.
If you were born after 1976, Professor Midgley adds, you’ve never experienced the global average temperature as Earth has increasingly become hotter ever since.
“In 2015 and 2016 the planetary warming was intensified by the weather pattern known as El Niño, in which the Pacific Ocean released a huge burst of energy and water vapour into the atmosphere,” writes Justin Gillis in The New York Times. “But the bigger factor in setting the records was the long-term trend of rising temperatures, which scientists say is being driven by increasing levels of carbon dioxide and other greenhouse gases.”
Bar some “crazy climatic event”, Earth won’t be cooling down in the near future, Professor Midgley says. And this is a troubling prospect, says Professor Will Steffen of the Australian National University and the Stockholm Resilience Centre, who led two studies detailing the detrimental effects of human activity on the environment.
Carbon dioxide levels are at an all-time high, British newspaper The Guardian reports, adding that the loss of biosphere integrity is resulting in species facing extinction 100 times faster than normal.
“If Earth is going to move to a warmer state, 5 to 6 °C warmer, with no ice caps, it will do so and that won’t be good for large mammals like us,” Professor Steffen says. “People say the world is robust and that’s true, there will be life on Earth, but Earth won’t be robust for us.”
While the newly anointed leader of the free world is refusing to face up to the threat that global warming poses, other leaders are committed to taking steps to combat it.
In the foreword to a new book, Climate Change, Prince Charles, heir to the British throne, describes it as the “wolf at the door” and the single biggest threat to life on Earth.
The book, which the prince co-wrote, details overwhelming scientific evidence that human activity triggered natural disasters such as the recent flooding in Britain.
Come hell or high water
The consequences we’ll suffer if temperatures continue to rise are fourfold, says Peter Johnston, a climate scientist at the University of Cape Town. Firstly, human beings will struggle in the increased heat, agricultural crops won’t grow, water might become scarcer and diseases and pests will thrive and be more difficult to control.
The poor will bear the brunt of these effects, he adds. “We’re literally living in a new age of consequence. We made our decision not to act fast enough on the burning of fossil fuels in the ’70s and ’80s and now we’re
‘If Earth is going to move to a warmer state . . . it wont be good’
reaping the consequences,” Professor Midgley says. The possible radical effects of prolonged climate change will become apparent only in the latter part of this century, he adds.
Human civilisation is sensitive to climate variability. Most of our largest cities are located on coastlines. This exposes urban populations to extreme storms.
“As you release more energy into the atmosphere, storms will become more vicious. This, combined with higher sea levels, means cities are literally sitting in the path of destruction.”
Professor Midgley cites Hurricane Irene, which hit New York in 2011, as an example of how the rich can quickly recover from natural disasters, while the poor are uninsured and vulnerable.
Will we survive?
History has shown that civilisations that rise and then stick to their core values without adapting may collapse, Professor Steffen believes. Some people say we can adapt because of technology, but he doubts that humans could survive a radical temperature change.
“There’s no convincing evidence that a large mammal with a core body temperature of 37 ⁰C will be able to evolve that quickly. Insects can, but humans can’t.”
Johnston disagrees. He says humans are accustomed to climate change and have already shown themselves capable of adapting. How else did people of European descent, accustomed to cold and little sun, evolve so quickly to survive in a tough African climate?
“We’re all going to die, but not because of global warming,” he quips. “We’re going to die sooner if we can’t adapt to the changes of global warming, but it’s a bit misleading to state that specifically this or that will happen.”
In South Africa climate scientists are already helping the government and private sector anticipate climate change. For instance, in the Western Cape, fruit farmers are receiving advice on how to grow their crops differently and adapt their irrigation practices.