By Jeremy Lovell LONDON, April 5 (Reuters) - Advertisements for flights, or holidays that include flying, should carry a tobacco-style health warning to remind people of the global warming crisis, a leading British think-tank said on Thursday. Using the traditional Easter holiday getaway to highlight the issue, the Institute for Public Policy Research said such health warnings would make people think twice about the impact their journey would have on the environment. "The evidence that aviation damages the atmosphere is just as clear as the evidence that smoking kills," IPPR climate change chief Simon Retallack said. "We know that smokers notice health warnings on cigarettes, and we have to tackle our addiction to flying in the same way," he added, calling for clearly visible warnings such as "flying causes climate change". Scientists predict that global average temperatures will rise by between 1.8 and 4.0 degrees Celsius this century, mainly due to burning fossil fuels for power and transport, putting millions of lives at risk from floods, famines and storms. Environmental campaigners say emissions of climate warming carbon gases at high altitude are more than twice as damaging as those at ground level and that people should be deterred from flying where alternatives are available. Although flying currently contributes relatively litle to the sum total of carbon emissions, the industry is booming and its emissions are expected to double or triple in coming years. "If we are to change people's behaviour, warnings must be accompanied by offering people alternatives to short-haul flights and by steps to make the cost of flying better reflect its impact on the environment," Retallack said. The IPPR called for the health warnings to carry detailed information on the amount of carbon dioxide each flight would emit per passenger and, where relevant, compare it with alternative means of transport like trains. To go alongside that, IPPR called for increases in aviation taxation to deter air travel and for carbon offsetting -- buying surplus emission certificates from elsewhere -- to become an automatic part of the flight ticket. The British government has come in for harsh criticism from environmentalists for promoting rather than trying to rein in surging air travel, refusing to tax air fuel in the same way as road fuel and putting only token taxes on passengers.
