For years, scientists and security analysts have warned that global warming looms as a potential source of war and unrest.
Storms, droughts, floods and spells of extreme heat or exceptional cold can all destroy wealth, ravage harvests, force people off land, exacerbate ancient rivalries and unleash a fight for resources.

These factors are predicted to become more severe as carbon emissions interfere with the earth’s climate system.
Yet some argue there is evidence that man-made warming is already a driver in some conflicts.

“In a number ‘of African countries, the increase in violent conflict is the most striking feature of the cumulative effects of climate change,” South Africa’s Institute for Security Studies warned in 2012.

The idea leapt to prominence in 2007, when UN chief Ban Ki-moon said violence in Sudan’s Darfur region was sparked in part by a two-decade decline in rainfall that devastated cattle herds.

Arab nomads were pitched against settled farmers in a rivalry for grazing and water. The tension bloomed into full scale confrontation between rival militias.

Others have drawn a link between the 2011 Arab Spring uprisings and climate change-induced heatwaves in cereal-exporting countries.
Russia, Ukraine and arid Kazakhstan all took their grain off the global market and, within four months, global food prices hit their second record peak in three years.

This may have lit the fuse in powder-keg Arab countries, according to this view.

Former US vice-president Al Gore, now a Nobel-honoured climate campaigner, believes climate change was a factor in the Syrian conflict.
Human security will be progressively threatened as the climate changes.

“From 2006 to 2010 there was a climate related historic drought that destroyed 60% of the farms in Syria, 80% of the livestock and drove a million refugees into the cities, where they collided with another million refugees from the Iraq war,” he said in Davos last month.

Not all experts agree and climate scientists are cautious about drawing a causal link between global warming and current conflicts – as opposed to future ones.”The example of Darfur is often put forward,” French climatologist Jean Jouzel writes in a new book. “But the reality is more complex, and most researchers acknowledge that the political and economic context was the prime factor.”

In the military though, it is different. Armed forces cannot wait until the proof is all there, which is why in many countries, military analysts already included climate change in risk management, said Neil Morisetti, a former British admiral and climate adviser to the British government.

“Some will say the risk is here already, “he said. “If you look at where climate change is going to have its greatest effect and is already having an effect, it’s that belt north and south of the equator … this is where a lot of raw materials are, where the world’s supply chains and trade routes run, and where ultimately a lot of the markets and emerging powers are.”

Experts are united in heralding worse to come. “Human security will be progressively threatened as the climate changes,” the UN’s Intergovernmental Panel on Climate Change warned in its overview report.

The Pentagon agreed. “Rising global temperatures, changing precipitation patterns, climbing sea levels and more extreme weather events will intensify the challenges of global instability, hunger, poverty and conflict,” it said last year. – AFP

BREACHING THE BOUNDARIES OF SURVIVAL

Human activity has pushed the planet across four of nine environmental boundaries, sending the world towards a danger zone, according to a study published recently in the journal Science.

Climate change, biodiversity loss, changes in land use and altered biogeochemical cycles, due in part to fertiliser use, have changed fundamentally how the planet functions, the study said.

These changes destabilise complex interactions between people, oceans, land and the atmosphere, said the paper titled “Planetary Boundaries: Guiding human development on a changing planet”, by 18 leading international researchers.

Passing the boundaries makes the planet less hospitable, damaging efforts to reduce poverty or improve quality of life.

“For the first time in human history, we need to relate to the risk of destabilising the entire planet” said Johan Rockstrom, one of the study’s authors and an environmental science professor at Stockholm University.

Scientists in 2009 identified the nine planetary boundaries within which humanity can develop and thrive. The five other boundaries, which are ozone depletion, ocean acidification, freshwater use, microscopic particles in the atmosphere and chemical pollution, have not been crossed.

Passing the boundaries does not cause immediate chaos, but pushes the planet into a period of uncertainty.

Scientists consider climate change the most serious.

The amount of carbon dioxide in the atmosphere, a gas causing the planet to warm, has exceeded 350 parts per million to the present 395 parts per million, crossing the boundary of what scientists think to be acceptable.

“We are at a point where we may see abrupt and irreversible changes due to climate change, said Rockstrom, as warming could cause Arctic ice sheets to melt, releasing more greenhouse gases and creating a vicious feedback loop.

The study results are to be incorporated into the new global development goals that will be finalised in September at the United Nations in New York to replace the Millennium Development Goals on poverty alleviation which expiring this year.

Scientists hope the new study will help balance competing demands for economic growth and environmental sustainability, which are likely to arise during the conference.

The debate over the reality of climate change rages on, with conflicting data confusing decisions and widening the gap between supporters and doubters.

In fact, despite the dire warnings, food prices have declined in the past four years, indicating that wild weather linked to climate change is not destroying harvests worldwide. Commodity prices, a measure of scarcity for energy and other basic goods, are also falling, leading some economists to question warnings from climate scientists.

However, “Just because we are not seeing a collapse today doesn’t mean we are not subjecting humanity to a process that could lead to catastrophic outcomes over the next century,” said Rockstrom. – Reuters.

INDICATOR SPECIES

Environmental indicators are simple measures that tell us what is happening in the environment. Since the environment is very complex, indicators provide a more practical and economical way to track the state of the environment than if we attempted to record every possible variable in the environment.

Indicator species are plants and animals that, by their presence, abundance, lack of abundance, or chemical composition, demonstrate some distinctive aspect of the character or quality of an environment.

An indicator species can be any biological species that defines a trait or characteristic of the environment. For example, a species may delineate an eco-region or indicate an environmental condition such as a disease outbreak, pollution, species competition or climate change. Indicator species can be among the most sensitive species in a region and sometimes act as an early warning to monitoring biologists.

In places where metal-rich minerals occur at the soil surface, indicator species of plants can be examined to understand the patterns of naturally occurring pollution, and they can even be a tool used in prospecting for potential ore bodies.

Often, the indicator plants accumulate large concentrations of metals in their tissues. Nickel concentrations as large as 10% have been found in the tissues of indicator plants in the mustard family (Alyssum bertolanii and A. murale) in Russia, and a concentration as large as 25% occurs in the blue-coloured latex of Sebertia acuminata from the Pacific island of New Caledonia. Similarly, Becium homblei, related to mint, has been important in the discovery of copper deposits in parts of Africa, where it is confined to soils containing more than 1,000 mg/kg of copper, because it can tolerate more than 7% copper in soil. So-called copper mosses have been used by prospectors as botanical indicators of surface mineralization of this metal in Scandinavia, Alaska, Russia, and elsewhere.

Plants are also used as indicators of serpentine minerals, a naturally occurring soil constituent that in large concentrations can render the substrate toxic to the growth of most plants. The toxicity of serpentine influenced soils is mostly caused by an imbalance of the availability of calcium and magnesium, along with the occurrence of large concentrations of toxic nickel, chromium and cobalt and small concentrations of potassium, phosphorus, and nitrogen. Serpentine soils are common in parts of California, where they have developed a distinctive flora with a number of indicator species, many of which are endemic to this habitat type.

Indicator plants also occur in many semi-arid areas on soils containing selenium. Some of these plants can accumulate this element to large concentrations, and they can be poisonous to livestock, causing a syndrome known as “blind staggers” or “alkali disease.” The most important selenium-accumulating plants in North America are in the genus Astragalus, of the legume family. There are about 500 species of Astragalus in North America, 25 of which can accumulate up to 15 thousand ppm (parts per million) of selenium in foliage. These species of Astragalus can emit selenium-containing chemicals to the atmosphere, which gives the plants a distinctive and unpleasant odour. In South Africa, the Karoo is a area of high soil selenium.

Indicator species can also be used as measures of environmental quality. For example, many species of lichens are very sensitive to toxic gases, such as sulphur dioxide and ozone. These “species” (actually, lichens are a symbiosis between a fungus and an alga) have been monitored in many places to study air pollution. Severe damage to lichens is especially common in cities with chronic air pollution, and near large point sources of toxic gases, such as metal smelters.

Similarly, aquatic invertebrates and fish have commonly been surveyed as indicators of water quality and the health of aquatic ecosystems. If a site has populations of so-called “sewage worms” or tubificids (Tubificidae), for example, this almost always suggests that water quality has been degraded by inputs of sewage or other oxygen-consuming organic matter. Tubificid worms can tolerate virtually anoxic water, in contrast with most of the animals of unpolluted environments, such as mayflies (Ephemeroptera) and stoneflies (Plecoptera), which require well-oxygenated conditions.

Another current example involves frogs and salamanders as indicator species. Populations of amphibians are declining on a global scale. Their decline is thought to be an indicator of tainted environments. Therefore, the numbers of amphibians worldwide are being closely monitored.
In a related example, the eggs of certain bird species are tested for the presence of organic pesticides. Remember Rachael Carson’s “Silent Spring” and the concentration of DDT in bird eggs.

FROGS, A CLASSIC INDICATOR SPECIES, ARE IN PERIL

GREY FOAM NEST TREE FROG

Many years ago in the wet season in Ndumo Game Reserve, a drive around the reserve revealed large white foam balls hanging from branches over the deeper and more permanent puddles. As a young ranger responsible for the twice daily tours around Nyamiti and through the Fig Forest, I had to quickly read up on this phenomenon so I could interpret it to the visitors, (no internet in those days!). This is the fascinating story I discovered.

The grey foam-nest tree frog or southern foam-nest tree frog (Chiromantis xerampelina) is a species of frog in the Rhacophoridae family. It is found in Angola, Botswana, Kenya, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia, and Zimbabwe, and possibly the Democratic Republic of the Congo and Somalia. Its natural habitats are subtropical or tropical dry forests, dry savannah, moist savannah, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, subtropical or tropical dry lowland grassland, subtropical or tropical seasonally wet or flooded lowland grassland, intermittent freshwater marshes, arable land, pastureland, rural gardens, urban areas, heavily degraded former forests, ponds, and canals and ditches.

The grey foam-nest tree frog mates in what is described as the most extreme example of polyandry of all vertebrates. The simultaneous polyandry begins when a female begins releasing eggs onto a tree branch. Up to 12 males then cluster around her and fertilise the eggs by producing sperm which they whip into a foamy ‘nest’ with their hind legs. The female will leave temporarily to rehydrate before returning to the nest, as the entire ordeal can last several hours. Offspring of these polyandrous encounters are more likely to survive than the eggs fertilised by a single male.

Prey includes grasshoppers, crickets, caterpillars, and beetles. These frogs are preyed upon by the boomslang Dispholidus typus, the vine snake Thelotornis capensis, and the large slit-faced bat Nycteris grandis. The foam nests are preyed upon by the African bullfrog, Fornasini’s spiny reed frog Afrixalus fornasini, and the Blue monkey Cercopithecus mitis.