NASA scientists have revealed that our planetary neighbour, Mars, is also experiencing global warming.

In research just out in Nature magazine, the researchers say Mars is heating up at a similar rate to earth.

One climate change sceptic here has seized on the study as a challenge to the assumption that climate change is caused by humans.

Jennifer Macey reports.

JENNIFER MACEY: The red planet is heating up, so much so that the polar ice cap on Mars has been disappearing over recent years.

Now scientists at NASA's Ames Research Centre in California have gone part of the way to explaining this change in the planet's climate, by researching changes in dust and reflected heat from the sun.

The research shows that between the 70s and 90s, Mars warmed by point 0.65 degrees Celsius.

Here on earth the average temperature rose by point 0.75 during the 20th century.

Doctor Charles Lineweaver heads the Planetary Science Institute Research School at the Australian National University's Mount Stromlo Observatory.

He says on earth greenhouse gases trap radiation from the sun, which causes temperature changes, while on Mars it's due to the red dust.

CHARLES LINEWEAVER: Every once in a while there's a giant dust storm on Mars, and we don't know why, and there's a feedback - the light comes in, it's either reflected or absorbed. If it is absorbed, that produces more heat, that produces more dust devils. The dust devils then raise some of the dust into the atmosphere and clear off some of the darker rocks, and that absorbs more sunlight, which produces more dust devils, et cetera.

JENNIFER MACEY: The climate modelling systems used by the NASA scientists to measure the temperature change on Mars are similar to those used to forecast the weather on Earth.

Professor Andy Pitman from the University of New South Wales is an expert on climate modelling, and was a lead author on the Intergovernmental Panel of Climate Change report released earlier this year.

ANDY PITMAN: The models that represent the Earth are vastly more complex than you would need to represent Mars. But the processes that are used to explain the results in the Marsian study, those mechanisms are included in the climate models used to project the future climate, and have been shown on Earth to be negligible in their significance.

JENNIFER MACEY: However, some global warming sceptics say the research does point to holes about climate change theories here on Earth.

William Kininmonth is the former head of the National Climate Centre at the Bureau of Meteorology, and the author of Climate Change: a Natural Hazard.

He says it's an interesting observation.

WILLIAM KININMONTH: The variability of climate on Mars suggest that there is an equal probability of, variability of climate on Earth, and the fact that both Mars and Earth are warming at the same period, we either look to coincidence, or we look to some common feature or common factor that's causing them both to warm a little.

JENNIFER MACEY: The University of New South Wales Professor Andy Pitman dismisses any connection between the warming on both planets as silly science.

ANDY PITMAN: There are no links, there are no common factors, there are no associations. It's entirely coincidental, and it's completely explicable by known mechanisms on both planets that are in no way related.

He must have been in the men's room when they covered the bit describing the fact that the Earth and Mars are in the same solar system, heated by the same sun, in the same cosmological time period. Certain dissenters of the anthropogenic global warming hypothesis state that: "New evidence shows that that as the radiation coming from the sun varies (and sun-spot activity is one way of monitoring this) the earth seems to heat up or cool down. Solar activity very precisely matches the plot of temperature change over the last 100 years. It correlates well with the anomalous post-war temperature dip, when global carbon dioxide levels were rising." ( http://www.channel4.com/science/microsites...rguments_5.html ) + http://www.timesonline.co.uk/tol/news/worl...icle1368920.ece