Last year was the hottest year in recorded history. It continued a trend of every year in the last decade being warmer than the one before. Nine of the ten hottest years in record happened in that same time period. This is despite all the things that traditionally make the world colder – less solar activity and more aerosols in the atmosphere – being dominant in the climactic system.
The odd year out was 1998. This corresponded with a strong El Niño. The phenomenon has a large-scale effect on sea surface temperatures, rainfall and air pressure. It starts when the sea surface temperatures in the central and eastern equatorial regions of the Pacific – to the east of Australia – rapidly increase. This weakens the trade winds that blow across the region, taking the brakes off a warm patch of water that is normally pushed into one area of ocean near Australia.
The water then heads east, towards the Americas, where it warms more of the Pacific. It also starts warming the atmosphere. This then has a knock on effect on local weather systems across the planet – generally warming the planet and leading to less rainfall in the southern hemisphere and more in the northern hemisphere.
A fairly regular phenomenon, the El Niño Southern Oscillation usually occurs around Christmas – hence Spanish-speaking fishermen off the South American coast naming it after the “Christ Child”.
It has been absent in recent years, but in early 2015 climate monitoring agencies around the world started noticing the moving of hot ocean water that is its hallmark. In its last El Niño update two weeks ago, the National Oceanic and Atmospheric Administration in the United States said El Niño conditions are present. “There is a greater than 90% chance that El Niño will continue through Northern Hemisphere winter 2015-2016 and around an 80% chance it will last through early spring 2016.”
The moniker of “Godzilla El Niño” has been given to this year’s incarnation because of it coming out of the oceans to the west of the Americas and its large-scale impact on the two continents.
Spanish publications in South America are already running stories about the drop in crop production that is facing the region as rainfall levels drop. The same level of concern is starting to show in the language being used in Australia with regards to El Niño.
In South Africa, the impact is lessened because of the distance from the Pacific Ocean, which is halfway around the world. But each El Niño season brings with it a drop in rainfall and a consequent lowering of agricultural yield. Droughts earlier this year have already cut the yield of maize by a quarter and five provinces are in the grip of a drought.
An International Monetary Fund paper on the phenomenon – “Fair Weather or Foul? The Macroeconomic Effects of El Nino.” – published earlier this year said all economies are impacted upon. “South Africa also experiences [above average] hot and dry summers during an El Niño episode.”
This drops agricultural yield, which makes up 10% of the economy. As a result GDP output in an El Niño year is lowered by 0.6%. Inflation is also increased by 0.1%, if the country is still exporting basic foodstuff. Thanks to the continuing drought, South Africa is an importer of staple food such as maize.
The fund’s paper said this sort of short-term economic slowdown was common in all Southern Hemisphere countries. The last strong El Niño pushed Indian inflation up by 0.5%, it said.
But for countries in the north, such as China and the United States, this meant a net benefit to their agricultural sector as exports increased to compensate for the crop failures in the south, the paper said.
The impact across the whole world economy is, however, significant. The paper said the warmer temperatures could create “food price and generalised inflation” which in turn “may trigger social unrest in commodity-dependent countries that primarily rely on imported food”. The paper said the economic consequences are “large, statistically significant and highly heterogeneous across different regions”.
The sentiment was echoed in last year’s release of the Intergovernmental Panel on Climate Change’s report into climate change. This UN body collates the science being done on the changing climate and publishes five-yearly reports for the use of policymakers.
The last one warned that without a reduction in carbon emissions, the impacts of climate change would be “irreversible”. The most vulnerable countries – most in the global south – would be adversely affected as crops failed due to unpredictable conditions, it said. This would in turn put more pressure on existing socioeconomic problems and lead to possible social unrest and even war.
The panel noted that the rate of warming had slowed down in the last decade to 0.04°C per decade, while annual temperature records were still being broken.
In the 1980s and 1990s it was 0.26°C per decade. But that slowdown was due to various things that drive down temperature: the sun was less active, the oceans taking up more heat and more aerosols from volcanoes and Asian factories blocking more incoming heat.
Last week the New Scientist compared different data sets to look at average global temperature increases, in a paper titled “Halfway to Hell”. This said that El Niño alone could bump up average global temperatures this year by 0.1°C – making this the hottest year in history by a considerable margin.
It would also see the world passing the landmark of being 1°C hotter than when the Industrial Revolution kicked off with humans emitting greenhouse gases into the atmosphere.
One degree is halfway to the two degree maximum increase international climate negotiations have set as a target for any global agreement. The UN’s climate body says that anything beyond that will lead to too many changes in the earth’s life support systems for much of current civilisation to survive.
This human impact on the world is so strong that the world is going through a whole new era – the Anthropocene. Named because humanity now has the biggest impact on how everything functions.
Last year was the hottest year ever recorded, and each year in the last decade has broken temperature records. South Africa’s interior is, on average, 0.6°C hotter than a century ago.
In December world governments will meet in Paris at the 21st Conference of the Parties to finalise a text that will help tackle this increase. If signed, this will see the world aim to go carbon neutral in this century.