Changing Climate …

IS CLIMATE CHANGING?

In 2002 and 2003, Australia experienced its worst drought in a century. At western Victoria’s Lake Corangamite, water levels sank so low that much of the lake’s bottom was exposed. Residents discovered, buried in the mud flats, bombs that had been dropped into the lake during a World War II bombing practice raid – undisturbed until uncovered by the ravaging drought.

The lack of rain devastated Australian farmers. Farming income dropped by 70% and the population of sheep, a mainstay of the Australian economy, fell to its lowest level since 1947. Grain production, too, plummeted by more than half. With temperatures rising and water in scarce supply, bush fires ran rampant. In January 2003, bush fires in Canberra, the nation’s capital, destroyed over 500 homes.

Drought continues in parts of Australia, particularly in the south and southwest. In many areas of the country, rainfall has long been declining; it has been diminishing in New South Wales for over 50-years. Australians now worry that drought has become a permanent condition.

 

Why is it so dry?

Trial by Fire

In 2003, the most devastating forest fires in 25-years blazed through Portugal. The flames damaged more than 2,500 houses and other buildings and destroyed over 400,000 hectares of land. This disaster was just part of a pattern: throughout the Mediterranean region, from Spain to Greece, wildfires have been on the increase for several decades.

New breeding programmes for the threatened Iberian-lynx are to be established in Portugal and Spain

Trees and property owners are not the only victims of conflagrations. In Portugal’s Monchique and Caldeirao mountains, animal habitats are being destroyed, placing further stresses on an already threatened and endangered species’ such as the Iberian lynx and the Boneilli eagle.

What is causing the fires?

Four Hurricanes

In 2004, Florida suffered more hurricanes in one season than any US state in more than a century. First, on the 13^th August, Hurricane Charley battered south-western Florida with winds exceeding 145 mph and waves of up to 10 feet. Charley claimed the lives of 31 people and caused estimated damages of up to $6.8 billion. The people of Florida were still recovering from this ordeal when Hurricane Frances slammed into the eastern side of Florida on September 5^th with winds of up to 110 mph. The storm uprooted trees, tore off roofs, smashed boats, and knocked-out power supplies for millions of people. Torrents of rain flooded streets and reduced visibility to almost zero. The Kennedy Space Centre suffered more damage than during any previous storm.

Those two hurricanes were followed by a third. Ivan, with winds that blew over 130 mph, hit Pensacola in Florida’s western panhandle after making landfall in Alabama on 16^th September. Finally, on the 25^th September, Jeanne, whose winds clocked 115 mph, swept ashore at almost the same location as Frances, scattering the debris created by that hurricane. Altogether, the four hurricanes killed 116 people and caused $17.5 billion in damage in Florida alone. Millions of Floridians were forced into evacuation shelters; thousands were left homeless. The last US state to have suffered four hurricanes in one season was Texas in 1886.

Why all the hurricanes?

Islands in Trouble

In Fiji, a South Pacific nation made up of hundreds of islands and atolls, people notice that things have changed. In the province of Nadroga, coastal flooding is increasing and the coastlines are eroding much faster. Tides come in farther than they used to. Freshwater is scarcer, and the soil is less stable. The villagers depend on the sea for food, but the local marine life has gone haywire. Coral reefs are bleached white, having lost the microscopic algae that live inside their cells. These microalgae nourish the reefs, creating good healthy habitats for the fish. As the reefs bleach and die, fish disappear. Octopuses spawn, now, during March, instead of November.

Villagers across the South Pacific islands tell similar stories of change: wind and rainfall patterns are not what they once were; small islets have been inundated by the ocean; potato and taro tubers rot in perpetually waterlogged soil. With sea levels rising, low-lying Tuvalu is considering moving its entire population to New Zealand.

Why are the islands in trouble?

Polar Bears at Risk

In the Arctic, Polar Bears are going hungry. In Canada’s Hudson and James bays, in the southern-range of these cold-adapted animals, cubs are starving to death for lack of food or because their nursing mothers lack the body fat they need to nourish their offspring.

The Canadian Government has been advised by a panel of experts that it should develop a plan to protect the country’s estimated 15,000 polar bears, which are at risk both from hunting and from the loss of summer ice in the Arctic - widely believed to be due to climate change.

The scarcity of food can be traced to changes in the ice. Polar bears normally live by hunting seals on the pack ice that covers the Arctic Ocean. In summer, when much of the pack ice has melted, many bears stay on land, living off the body fat built-up during hunting seasons. But the ice has melted earlier in recent springs and has formed later in fall, shortening the period when polar bears hunt and build-up fat reserves for summer. For every week of hunting time lost, bears weigh about 10 kg less. The weight loss leaves them in poorer condition, less able to reproduce or to produce healthy offspring – and in greater danger of local extinction.

Why is the ice melting?

 

 WEATHER vs. CLIMATE

Stories of extreme weather are always with us – floods, droughts, tornadoes and blizzards. But around the world, from Florida to Fiji, from Australia to Portugal to the Arctic, extreme weather appears to be becoming more frequent. What is causing all of these dramatic events? Are they examples of climate change? Or, are they merely coincidence, an unlikely run of bad and extreme weather? Is human activity a factor?

Weather is the atmospheric state in a given place and time; climate is a locality’s weather as observed over a long period – in other words, the long-term behaviour of weather. Climate varies from region to region, but its long-term stability is part of what gives every region its character. Climate is hot and dry in deserts, warm and wet in tropical rainforest; climate changes seasonally from warm to cold in temperate zones. The climate of the African savannah has been stable enough to make it a durable habitat for lions and zebras, while the snow that covers the regions around Moscow for nearly six months falls reliably enough to make it part of the city’s identity. Around the world, human beings, like all other organisms, depend on climate remaining about the same. They rely on the steadiness of climate to make travel plans, commute to work, plant crops, build houses and start businesses. A change in the world’s climate would be a universal cause for concern. Climate has changed before in Earth’s history but the question that needs an answer is, ‘Is climate changing now?’

Because climate can only be measured over the long-term, no single weather event can be reliably attributed to climate change. Weather varies naturally from year to year, and not every variation signals a change in climate. Startling as it was for four hurricanes to strike Florida in one season, that episode alone cannot lead us to conclude that from now on Florida will experience four hurricanes annually. Long-term study of a region’s weather is necessary to establish whether the climate is changing, and in what direction.

It is even harder to determine what is causing climate-related events. On the broadest scale, climate is influenced by five components: the atmosphere (air), the lithosphere (solid Earth), the hydrosphere (liquid water), the cryosophere (ice and snow) and the biosphere (the totality of life on Earth). These can be considered five parts of one climate system, with the Sun as the power source that drives most of the phenomenon. The interplay of these factors is extremely complex. Causation is difficult to trace.

 

HARD EVIDENCE

The news and media is full of stories about climate change; many contend that it is driven by human activity. Global warming, many claim, is being caused by the burning of fossil fuels that emit heat-trapping greenhouse gases.

Some scientists say global warming can cause fiercer hurricanes, but does that mean that hurricanes Charley, Frances, Ivan and Jeanne were caused by climate change? Are rising sea levels, which will make hurricanes more damaging, also caused by climate change?

For many years now, evidence from around the world has been mounting that the global climate is indeed changing. Conditions and events that have been documented by climate researchers indicate that temperatures are rising around the globe. Glaciers are melting faster, and the danger to low-lying coasts like those of the South Pacific islands is real. The patterns of the winds around the Antarctic are changing, dragging rain away from Australia and bringing drought. The fire’s ravaging Europe’s forests, though probably aggravated by poor land use practices, are being fed by growing dryness and warmer temperatures. Global warming is melting the pack ice on which polar bears depend.

Is human activity contributing to this change? Or, could it be part of a natural cycle? Is it different from past climate changes?

The answer to the first question has become increasingly clear as evidence continues to mount. That answer is yes. Human activity is indeed contributing to climate change; natural processes alone cannot account for the massive changes that scientists have observed and recorded from around the world.

Since 1988, the UN Intergovernmental Panel on Climate Change (IPCC) has involved more than 3,000 scientists worldwide to examine our understanding of climate change. In 2001, it reported that:

… Earth’s climate system has demonstrably changed on both global and regional scales since the pre-industrial era, with some of these changes attributable to human activity.

The levels of carbon dioxide – a gas normally present in the atmosphere but also produced from burning fossil fuels – is higher now than it has been for millennia. Scientists have little doubt that this, and other gases released by human activity, is preventing heat from escaping from the planet. This is causing global temperatures to rise faster than at any time during the past thousand years.

 

ENGAGING THE LONG VIEW

The climate is getting warmer, and human activity is contributing to that warming – that much is clear. What, if anything, can be done to stop global warming? How bad will it get if nothing is done – or not enough? What consequences has climate change had in the past? And how can people help themselves and the world’s ecosystems to adapt to changes that are already too late to prevent?

In attempting to answer these questions, it is helpful by taking a long view. The Earth’s climate, for instance, has gone through many radical changes, travelling between ice ages and hot-house periods, long before humans ever appeared on the scene. The present climate crisis makes some sense in the context of that history, which shows that the forces that shape climate are complex, and that climate’s effects on people (and on other living things) are far ranging and profound.

 

© Mark Dowe 2008: all rights protected

 

- The writer campaigns on behalf of WWF (Scotland)

 

Related issue:

• Guardian Editorial, “Go against the flow”

- Article considers the scarce supply of water after a recent WWF report.

Writing in response:

A good article by the Editor of the Guardian.

Water is a scarce resource despite how we all take for granted its easy and open availability. With increasing droughts and periods of warmer temperatures expected through global warming in the years ahead, and with the increasing likelihood that diseases such as malaria and typhoid will manifest, water does happen to be the key in sustaining life on earth.

A recent Guardian Editorial highlighted the important point, too, of an ‘engineering scarcity’ which coupled with the Editor’s article here suggests potential difficulties on the horizon not yet fully publicly accepted.

Any ‘water footprint’ would naturally absorb idiosyncratic consumption whether that is for personal, domestic or consumed via other means. Extracting water content, for instance, in that calculation from a can of Coke does seem a little far fetched and would suspect a degree of pragmatism if such a footprint was ever to be introduced.

© 2008