Is this our gift to future generations? - National - theage.com.au

DANDENONG may be the new Brighton as Port Phillip Bay rises and the state's coast is lashed by more frequent violent storms over the next 60 years, new research into the effects of global warming has revealed.

Fears have also emerged that in the worst-case scenario, Melbourne landmarks such as Luna Park and Crown Casino may be under up to six metres of water as much of the city sinks. "Obviously six metres is going to create major problems for central Melbourne," says Professor Will Steffen, who has just written a report for the Federal Government warning of the looming crisis. "But the thing people really ought to be worried about is that we could see up to a metre rise in sea levels this century.

"It's at the top end but I don't think it's out of the realm of possibilities."

That would put much of Altona, the Docklands, Middle Park and Point Cook underwater and threaten St Kilda, Elwood and Port Melbourne. The race that stops a nation may also be under flood-watch, with the banks of the Maribyrnong River likely to breach low-lying Flemington.

The most recent serious flood was in 1972 when the city centre was inundated, but the most significant was the "great flood of 1891", which occurred after two days and nights of rainfall, and caused the Yarra to swell to 305 metres wide.

According to The Age report at the time, 3000 people, mainly in the inner-city suburbs of Collingwood, Richmond and Prahran, had to vacate their houses and two large lakes formed on the east and west sides of Chapel Street.

In 1934, ferocious storms caused widespread destruction to the entire city. Eighteen people drowned and 6000 were left homeless. In one hour on February 17, 1972, a then record 78.5 millimetres of rain dumped 100,000 tonnes of water on one square kilometre in the city. Elizabeth Street was a raging torrent.

Flood prevention measures have since been implemented but scientists say they will be insufficient in the face of global warming. They say the solution lies in reducing carbon emissions, but how this is done is a political hot potato.

The Prime Minister has called for debate about nuclear energy but the Opposition and green groups including Greenpeace say fundamental issues such as waste disposal and cost still haven't been resolved. They say the focus should be given to renewable energies like solar.

Since the industrial revolution, increasing levels of carbon dioxide and other gases have allowed heat from the sun to penetrate the Earth's atmosphere but at the same time prevented it from escaping.

The best estimate of the rise in global surface temperature since the middle of the 19th century is 0.6 degrees, and could be as high as 0.9 degrees. As the world's dependency on carbon-based fuel, such as coal and oil, shows no sign of abating, scientists say soaring temperatures will cause more violent storms as sea levels rise, destroy ecosystems and paradoxically threaten a new ice age.

Professor Steffen, the director of the Centre for Resource and Environment Studies at the Australian National University who spent seven years in Stockholm heading a global project on the effect of carbon production on the environment, says previous estimates of temperature rises have woefully underestimated the problem.

The Intergovernmental Panel on Climate Change, the global monitoring body, previously thought temperatures would rise between 1.4 and 5.8 per cent by the end of the century but new research methods reveal it could be higher and sooner.

"The situation is more serious than we thought five years ago," says Professor Steffen. "Impacts are discernible now, they are coming a little earlier than we thought and the risk that we may be going up to the higher end of the (temperature) range is larger than we thought. All this paints a scientific picture that places more urgency on the issue."

Global warming appears to have arrived in Australia, with last year the hottest on record. Sceptics had used El Nino to dismiss previous "record" years in 1988, 1989 and 2002, but last year there was no El Nino and April had a mean temperature of 2.58 degrees above the April average for 1961-1990.

This may not seem significant but the environment in which we live is finely balanced. Examples of the changes higher temperatures have wrought are not difficult to find, from bleaching of the Great Barrier Reef to heat-seeking cockroaches migrating to Melbourne from Sydney.

Still, the recent influx of insects is the least of Victoria's problems.

Since accurate satellite records became available in 1978, the floating ice-cap in the Arctic Ocean has shrunk 20 per cent and shows no signs of slowing. According to projections, the Arctic could be ice-free in summer months by the end of the century — something that has not occurred for at least the last million years.

The loss of the large ice sheet covering most of Greenland is scientists' greatest fear as this will produce six-metre sea-level rises. The sheet lost 16 per cent of its area between 1979 and 2002, and 208 cubic kilometres in the past year alone. It is now melting twice as fast as previously believed. However, due to thermal inertia it is unlikely to completely melt for another 500 to 1000 years.

In an interview in 2004 Jonathan Overpeck, director of the Institute for the Study of Planet Earth at the University of Arizona, was asked what he thought would happen if the Greenland ice sheet started falling apart. "The consequences would be catastrophic," he said. "Even with a small sea-level rise, we're going to destroy whole nations and their cultures that have existed for thousands of years."

The Antarctic has lost 87 per cent of its ice shelves since the 1950s and following the collapse of the Larsen ice shelf in 2002, the flow rate of glaciers has increased significantly.

Melting ice is only half the problem. Much of the rise in sea levels will come from water expanding due to warmer ocean temperatures.

The CSIRO's sea level expert, Neil White, says as the Earth warmed during the last century, sea levels rose between 10 and 20 centimetres — faster than the earth has seen for 3000 years — and are now creeping up by 3 millimetres a year. It is already having devastating consequences for low-lying islands.

"The underlying rate of sea-level rise around Australia is likely to increase considerably in coming decades," Dr While says. "This will result directly in shoreline retreat. More serious consequences will result from the increased impact of extreme events such as storm surges caused by tropical cyclones and mid-latitude storms, leading to coastal damage and flooding."

As much of the damage will be caused by storm surges, the CSIRO's Dr Kathy McInnes and Duncan Malcolm of the Gippsland Coastal Board are in the midst of a study into how surges are affected by higher sea levels.

Unpublished preliminary findings suggest that by 2070 Victoria's southern and eastern coasts may be hit by storm surges with wind speeds 10 per cent greater than present. Based on figures from insurer IAG, a 25 per cent increase in peak wind gusts causes a 650 per cent rise in building damage.

Last month six of Australia's largest companies came together with the Australian Conservation Foundation to push for a reduction in carbon emissions.Of the 40 most expensive insurance claims since 1970, 34 were weather- related, says Bruce Thomas of reinsurer Swiss Re. A couple of big storms could wipe out the insurance sector and cripple the entire world economy, he says.

Professor Steffen says: "This isn't a fringe issue, it is centrally important for our future. We humans in the past have shown ourselves to be quite resourceful and inventive so by no means is this doom and gloom. What it is saying is if we ignore it, we are ignoring it at our peril."

Global warming: the facts
GLOBAL surface temperature has risen 0.6 degrees since the late 1800s.
■Since 1976, the rise has been faster, at 0.18 degrees a decade.

■The 1990s was the warmest decade, with an average rise of 0.38 degrees in the northern hemisphere and 0.23 in the southern hemisphere.

■Temperatures are predicted to rise 1.4 degrees to 5.8 degrees by the end of the century.

■Last year was Australia's hottest year on record. April recorded the largest monthly rise — 2.58 degrees above the 1961-1990 April average.

■Scientists believe that 2050 is the "tipping point", that is when so much damage has been done that it can't be corrected.

■The Intergovernmental Panel on Climate Change says carbon emissions must fall 60 per cent below 1990 levels before 2050.

■World population is expected to rise 37 per cent by 2050.

WHAT YOU CAN DO
SCIENTISTS say that unless we dramatically reduce greenhouse emissions by 2050 we will reach what they call the "tipping point", where the damage to the Earth's environment becomes irreversible.
Households generate almost one-fifth of the country's greenhouse gasses — about 15 tonnes per household every year — through daily activity such as transport, energy use and the decay of waste in landfill, according to Federal Government agency, the Australian Greenhouse Office.

The good news is that households can reduce their ecological footprint without too much sacrifice.

■Switch to green energy. This doesn't mean your home will be wired up to a wind farm, but some of your energy will be sourced from alternative and renewable energy sources. Most utilities offer this option for about an extra $1 a week.

■Solar power. This may seem expensive but once Federal Government rebates are included, solar panels should start to make savings before the warranty expires. Based on the average family power bill, a 1kW model costing about $12,000 will cut the energy bill in half. This model also attracts a rebate of up to $4000 and has a working life of about 25 years.

■Solar Hot Water. Based on an average family bill, a solar hot-water system costing about $3000 will pay for itself within eight to nine years. It has a working life of 25 years. The State Government also offers a rebate of up to $1500.

■Energy Ratings: The energy rating system is a mandatory national labelling scheme for refrigerators, freezers, washers and dryers, dishwashers and air-conditioners. The higher the star rating, the bigger the emissions savings.

■Cooling: Fans are the cheapest to run and have the least greenhouse impact, though they only circulate air to create a "cooling" breeze. Evaporative coolers can lower the temperature by about 5 degrees. They operate at a fifth of the running cost and produce less greenhouse gases than an air-conditioner.

For energy-hungry air-conditioning to work at peak efficiency, the house or room should be sealed and highly insulated with windows shaded.

■Heating: The first step to keeping warm is good insulation and placing draft-stoppers under doors. Small common-sense measures can make significant savings.

The type of fuel that households use to generate heat will determine the cost, both in financial and greenhouse terms.

Natural gas is the best option, as it is cheaper than running an electric heater and produces much less carbon dioxide. An open fire releases about 1.5kilograms of CO2 per kilogram of wood.

■Transport: If public transport is not an option, there are two hybrid cars on the market: the Toyota Prius (starts at $37,000) and the Honda Civic Hybrid ($31,990). The Green Vehicle Guide rates the Prius 8.5 out of 10 for emissions and the Civic, 8. By way of comparison, the non-hybrid Civic rates 7 and the Toyota Camry 5.5.