Tag: Climate change

10th January 2016

FACT SHEET: Why Africa is vulnerable to climate change (Part 2)

This article first appeared on AfricaCheck.

Researched by Sarah Wild

Africa as a continent will be particularly vulnerable to climate change, or so the United Nations’ Intergovernmental Panel on Climate Change has been saying since 2001. Some scientists even think it will be the continent hardest hit by climate change.

As we discussed in our previous factsheet, to a large degree this is because Africa straddles the equator and has two arid and semi-arid zones on either side of the tropics.

But that’s only part one of the story. Here’s what’s set to happen when things heat up.

1. Expanding dry areas

Semi-arid areas are thought to be particularly vulnerable to climate change, says the inter disciplinary research group Adaptation at Scale in Semi-Arid Regions (ASSAR) at the University of Cape Town. That’s because these areas are already climatically stressed with high temperatures, low rainfall and long dry seasons.

“Semi-arid ecosystems are highly dynamic, with bursts of productivity in the wet season and in good years, and [with] very low productivity in dry years, often leading to temporary or longer term land degradation,” Mark New, director of the university’s African Climate Development Initiative, wrote in a note on ASSAR’s website.

The UN climate change panel noted in its fourth assessment report – published in 2007 – that by 2080 arid and semi-arid land areas in Africa are projected to increase by between 5% and 8% under a range of climate scenarios.

While climate change will not affect all regions on the continent adversely, as these arid and semi-arid areas expand, more people will fall into these zones.

2. Relying on rain

Africa already has a number of countries facing semi-arid conditions, which poses challenges to agriculture, the UN panel’s fourth assessment report noted.

That’s because arid and semi-arid zones are characterised by erratic and low rainfall of less than 700 mm per year as well as droughts every so often, explains the community adaptation and sustainable livelihoods unit at the global non-profit International Institute for Sustainable Development.

“Regarding livelihood systems, in general, light pastoral use is possible in arid areas and rainfed agriculture is usually not possible. In semi-arid areas, agricultural harvests are likely to be irregular, although grazing is satisfactory,” the unit further says.

Climate change is expected to cause a shorter growing season and force large tracts of peripheral agriculture out of production, the fourth UN report noted.

Rain-fed agriculture accounts for 95% of farmed land in sub-Saharan Africa, according to the International Water Management Institute, a non-profit science organisation. This practice “exposes agricultural production to high seasonal rainfall variability”, according to a paper published in the journal Ecological Economics.

“Agriculture is a huge issue, especially because African agriculture is not irrigated,” says Guy Midgley, a Stellenbosch University scientist involved in writing the climate change panel assessment reports. “Also, [African farmers grow] maize, which is not well suited to African environments.” That is because the crop is sensitive to drought and extreme temperatures.

Maize production is expected to decrease as climates change, as this paper shows. While the average predicted for the continent and Latin America is a 10% decrease, some areas may see more.

Midgley describes Africa’s reliance on maize as an “own goal”. “It’s a tragedy and a pity that it’s become entrenched.”

3. Diseases change with the climate

Changing climates are also likely to change disease patterns. Malaria is the best example of this.

The World Health Organisation estimates there were 214 million cases of malaria this year and 438,000 deaths this year. The mosquito-borne disease disproportionately affects sub-Saharan Africa, which is thought to account for 89% of malaria cases and 91% of deaths, the organisation says.

Although great strides have been made in curbing malaria – cases have fallen by 37% globally between 2000 and 2015, the WHO says – climate change may undo some of these gains.

For example, rising temperature has been shown to affect mosquito population numbers, and how the malaria parasites develop in their hosts, the authors of a paper published in the journal Science explained. They studied malaria incidence in the highlands of Ethiopia and Colombia.

The researchers further noted: “[There will be] an increase in the altitude of malaria distribution in warmer years, which implies that climate change will, without mitigation, result in an increase in the malaria burden in the densely populated highlands of Africa and South America.”

4. One catastrophe away from extreme poverty

The major reason that Africa is vulnerable to climate change, though, is that many of its inhabitants are poor.

A report published by the World Bank this year notes that rising temperatures could push another 100 million people into extreme poverty. Titled Shock Waves: Managing the Impacts of Climate Change on Poverty, the authors write: “The poor live in uncertainty, just one natural disaster away from losing everything they have.”

That is because climate-related catastrophes — a natural disaster, a crop failure due to drought, an increase in disease or a farmer’s herd wiped out, for example — can be too much for vulnerable people to recover from.

“Such events can erase decades of hard work and asset accumulation and leave people with irreversible health consequences,” the report stated.

Adaptation: Communities are doing it for themselves

In its fifth assessment report, the UN climate change panel noted: “Most national governments [in Africa] are initiating governance systems for adaptation.” For example, the Nile Basin Initiative bring together governments of the 11 countries through which it passes to coordinated all development activities and programmes on the river.

Climate scientist Bob Scholes, a distinguished professor at the University of Witwatersrand’s Global Change and Sustainability Research Institute, believes that when people say “Africa will be hardest hit by climate change” they mean the continent has a poor capacity to cope with climate disaster.

“Government and civil society responses [in many African countries] are not as strong as in other places,” he says. “But while [that poor coping capacity] is true at government level, it is not true at village and town level.”

“Because of the lack of government support, I find African societies quite resilient.”

10th January 2016

FACTSHEET: Why do many scientists think Africa will be hardest hit by climate change? (Part 1)

Researched by Sarah Wild

This was first published by AfricaCheck.

The world’s leading climate scientists will meet this month in Paris at the Congress of the Parties 21 (COP21) to hammer out an international agreement to attempt to keep global warming below 2° C compared to pre-industrial levels. The 2° C target was chosen because it represents “the maximum allowable warming” to avoid dangerous man-made interference in the climate.

The UK Met Office announced earlier this month that average global temperatures had already increased by one degree above pre-industrial levels. This was based on a dataset jointly run by the Met Office and the climate research unit at the University of East Anglia.

But these temperature increases will not be uniform: some places will record greater rises in temperature than others. The difference in temperatures is one of the reasons why many scientists think Africa would be hardest hit by climate change.

UN assessment reports stated risk

General view from the Nobel Peace Prize Ceremony in Oslo’s City Hall on 10 December 2007, in which the Intergovernment Panel on Climate Change were awarded the 2007 Nobel Peace Prize. Photo: AFP/Heiko Junge/SCANPIX NORWAY

“The idea that Africa would be the hardest hit started in the UN’s [Intergovernmental Panel on Climate Change] third assessment report in 2001… and the fourth report allowed this conclusion to be drawn,” Guy Midgley, a Stellenbosch University scientist involved in producing the reports, told Africa Check. “It’s pretty much become embedded in the global change common understanding.”

The United Nations’ Intergovernmental Panel on Climate Change is the major repository of climate research and technical information drawn from scientists across the world. It has produced five assessment reports on the state of climate change, starting in 1990, with the latest one published in November 2014. Midgley was part of the international team that shared the Nobel Peace Prize in 2007 for producing the fourth assessment.

The UN’s third report stated “Africa is highly vulnerable to the various manifestations of climate change”.

In the fourth report (2007), this became: “Africa is likely to be the continent most vulnerable to climate change. Among the risks the continent faces are reductions in food security and agricultural productivity, particularly regarding subsistence agriculture, increased water stress and, as a result of these and the potential for increased exposure to disease and other health risks, increased risks to human health.”

Midgley said that after the strong statement about Africa’s vulnerability, “[the fourth report] then goes on to list a range of adverse impacts which, taken together, have led to the conclusion that Africa will be the hardest hit”.

Following the fourth report, the African Ministerial Conference on the Environment (AMCEN) compiled a factsheet for the United Nations Environmental Programme. It said: “No continent will be struck as severely by the impacts of climate change as Africa. Given its geographical position, the continent will be particularly vulnerable due to the considerably limited adaptive capacity, exacerbated by widespread poverty and the existing low levels of development.”

However, this statement was compiled by ministers and not scientists.

‘Africa already quite hot’

While scientists and policymakers agree that African countries will be vulnerable to climate change for myriad reasons, there are still many gaps in our understanding of exactly how climate change will affect different parts of the world, different places within the different continents and to what extent.

Climate scientist Dr Bob Scholes is more sceptical than Midgley about the claim that Africa will be the continent hardest hit by climate change. Scholes, a distinguished professor at the University of Witwatersrand’s Global Change and Sustainability Research Institute, is another author of the Intergovernmental Panel on Climate Change’s assessment reports.

“The claim is based on two things: geographically and climatically Africa is exposed,” he told Africa Check. “Africa in general is already quite hot. Heat it up more and it’s just downhill for animal production, plant production and human health.”

However, other parts of the world are also quite hot and have their own vulnerabilities. And there are a number of regions within the African continent.

“In general, I would support the argument that Africa is vulnerable. But ‘the most vulnerable’? That gets into [the realm of] hyperbole,” Scholes said.

A geographic disadvantage

One of the reasons that African countries are vulnerable to climate change is the continent’s geography.

“Africa straddles the tropics with vast semi-arid regions on either side,” said Midgley. These arid and semi-arid areas are likely to see higher temperature increases than other areas, skewing the average temperature rise for the continent.

The UN’s fifth assessment report explainedthat it is “likely that land temperatures over Africa will rise faster than the global land average, particularly in the more arid regions, and that the rate of increase in minimum temperatures will exceed that of maximum temperatures.”

Drastic temperature increases between 1961 and 2010

Additionally, research by a team of international and South African scientists published earlier this year found that parts of subtropical and central tropical Africa had already shown drastic increases in temperature between 1961 and 2010.

“Over these regions, temperatures have been rising at more than twice the global rate of temperature increase,” the researchers noted.

Temperatures are projected to increase in these areas during this century “with plausible increases of 4 to 6° C [relative to the present day climate] over the subtropics and 3 to 5° C [relative to the present day] over the tropics by the end of the century”. This would happen, the researchers said, in the UN’s “low-mitigation scenario” – where countries put few measures in place to stop climate change.

Principal researcher and study leader, Dr Francois Engelbrecht from South Africa’s Council for Scientific and Industrial Research, said in September: “If negotiations [in Paris] fail to ensure a high-mitigation future, we are likely to see rapidly rising surface temperature across the continent…

“For many regions, the impact of temperature increases on the agricultural and biodiversity sectors may be significant, stemming from temperature related extreme events such as heat waves, wild fires and agricultural drought.”

Temperature only one element of vulnerability

Temperature increase is only one of the variables determining a country or a continent’s vulnerability, as wealth and infrastructure, among other things, also help to determine its ability to adapt to climate change.

“Australia is also beset by a very dry portion of its continent,” noted Midgley. “But from a vulnerability and exposure point of view, Africa is more vulnerable because of poverty.”

Or as the third assessment report puts it: “The adverse impacts of climate change are expected to fall disproportionately upon developing countries and the poor persons within those countries.”

‘We need an operating manual for the planet’

While scientists like Midley and Scholes may disagree about the extent of Africa’s vulnerability, there is no doubt among the thousands of scientists that contribute to the UN assessment reports that climate change is real and driven by human activities. However, more scientific research needs to be undertaken to understand how ecosystems will be affected.

“We don’t have an operating manual for the planet,” Midgley said, “and we need one.”

10th January 2016

South Africa needs to understand local climate change

“We’re already on course for a world that is different to the one experienced by humanity since its evolution,” climate scientist Bob Scholes told the Science Forum on Tuesday.

This month, the world’s leading climate scientists and policy makers met in Paris to hammer out an international agreement in an attempt to constrain global temperature increases by two degrees Celcius above pre-industrial levels.

However, the UK MET office announced last month that average global temperatures had already risen by one degree.

“Over the last 10,000 years, the climate of the world has been remarkably stable…. It became possible to have agriculture, complex civilisations, which obviously led to science,” said Scholes, who has contributed to the United Nations’ Intergovernmental Panel on Climate Change’s (IPCC’s) assessment reports and is a distinguished professor at the University of Witwatersrand’s Global Change and Sustainability Research Institute.

However, “Southern Africa warms up at twice the global rate… Day-time temperatures have increased by half a degree in the last century, but night-time seen a 2.44 degree increase,” he noted.

In the “Change is in the Air” report, launched by the South African Environmental Observation Network on the sidelines of the forum, the authors note that while work has been done in other parts of the world to understand how temperature changes will affect ecosystems, more research is needed to understand what will happen in South Africa.

“South Africa covers less than 1% of the world’s land surface and is home to nearly 10% of the world’s plant species, about 7% of the world’s vertebrates and 5.5% of all known insect diversity,” they write. Industries, such as tourism, and economic livelihoods depend on these ecosystems.

“The effects of warming on species’ ranges are widely reported [in cooler parts of the world, such as the Northern Hemisphere] and many people and policy makers assume that plants and animals will respond in a similar manner across the world.”

However, this is not the case. In a semi-arid country like South Africa, the availability of water is just as important. “It is important to understand that the impacts of global change vary across the world and a local perspective and local information is required to understand changes in our own areas, project their likely outcome, and plan accordingly,” the authors write.

Stellenbosch University scientist Prof Guy Midgley referred to this as an “operating manual for the planet”. Midgley, who returned to science after being involved in the IPCC, said he returned to research because “what you realise [being involved in the IPCC] is that we’re trying to make policy with imperfect science. Someone has to keep doing science. There is still quite a lot of uncertainty about how the world works. We don’t have an operating manual for the planet, and we need one.”

While Scholes said that there is not a hard threshold “when the wheels fall off, the risk [of extreme weather events and natural disasters] goes up”.

However, there are non-negotiable thresholds, he said. These include the melting point of ice – because as temperatures rise, the tundra in the Arctic and Antarctic will melt – and the body temperature of warm-blooded mammals.

“You and I all have body temperatures within fractions of degrees of each other. It is the same for all warm-blooded animals,” Scholes said. “As temperatures rise, we struggle to control our body temperature. Our [human] productivity drops about a quarter for every two-degree increase in temperature. Livestock fail to produce milk and breed.”

But, at the same time, animals and ecosystems are more susceptible to the rate of change, rather than incremental change. If temperatures increase slowly, ecosystems adapt, but … if the climate changes too fast, it runs ahead of them [ecosystems and animals].”

However, this rate of change works both ways. While humans needed to curb emissions to stop an escalation in temperature, “trying to reduce emissions too fast would also cause problems”, Scholes said.

NOTE: This is part of a series produced for Independent Newspapers’ post-Science Forum supplement.

6th September 2015

Researchers plug carbon sink gaps

The stormy waters south of the Cape suck carbon dioxide out of the atmosphere and are key to understanding what will happen to our climate as the Earth heats up.

The storms are part of the reason the Southern Ocean is one of the most under-researched in the world, although it absorbs almost half of the world’s man-made carbon emissions.

Last week, more than 50 researchers returned from a scientific voyage of the waters encircling Antarctica, the first leg of a two-year experiment – the third Southern Ocean Seasonal Cycle Experiment – that aims to fill in many of the blank spaces about how this ocean mitigates the effects of climate change.

A report from the United Nation’s Intergovernmental Panel on Climate Change, released last year, says the world is already experiencing climate change. “African ecosystems are already being impacted by climate change, and the future impacts are expected to be substantial,” it said.

Mediating global climate
Pedro Monteiro, chief oceanographer of the Council for Scientific and Industrial Research and head of the CSIR’s Southern Ocean Carbon-Climate Observatory programme, says: “Globally, there is a renewed interest in understanding what is going on in the Southern Ocean from a climate perspective and how it mediates global climate.

“Although anthropogenic carbon dioxide emissions – those created by humans – are well studied and account for about 10 gigatonnes per year, the natural carbon cycle between the ocean and the atmosphere is substantially larger at 100 gigatonnes per year and is less understood,” he says.

But, because of the stormy and cold weather in the Southern Ocean, researchers struggle to obtain scientific measurements during winter, something that this experiment plans to change.

For more, find the article — originally published in Mail & Guardian — here.