By Jeremy Lovell LONDON, March 7 (Reuters) - The British government is missing many of its own key environmental targets and must radically raise its game in the battle against global warming, one of its own watchdogs said on Wednesday. A Sustainable Development Commission (SDC) report said many government departments were producing more waste, more carbon, more water and using energy less efficiently than in 1999. "Overall, government performance is simply not good enough," said SDC chairman Jonathon Porritt. "Against a background of non-stop messages on climate change and corporate social responsibility, the government has failed to get its own house in order. It is absolutely inexcusable that government is lagging so far behind the private sector." The government has set itself a target of cutting carbon emissions by 12.5 percent by 2010, but the SDC said on average departmental emissions had dropped by just 0.5 percent since 1999, and 15 actually increased emissions last year. Lead offender, the Department of Transport actually boosted emissions of carbon dioxide -- the main global warming gas -- from road transport by 40 percent since 2002, the report said. "As for energy and carbon emissions, a drastic change in approach is essential for the government to have any hope of meeting its targets," the SDC report said. The government has also set a target of cutting water usage to 7.7 cubic metres per head. But its average consumption was 10.2 cubic metres, and the Cabinet Office consumed 19 cubic metres. "Unless government can quickly take charge of its own operations, it risks breeding deep cynicism amongst the general public," said the report, entitled "Sustainable Development in Government." Next week the government, priding itself on taking a lead in the international battle against global warming, will publish a draft Climate Change Bill that will set in law a goal of cutting national CO2 emissions by 60 percent by 2050. But environmental expert and author Chris Goodall notes in his book "How to live a low-carbon life" that targets the government set itself in 2000 to slash carbon emissions by 2005 had all been missed. In fact, he wrote, actual carbon dioxide emissions in 2005 were four million tonnes higher than they were in 2000. He argues that far from setting a 60 percent carbon dioxide emissions cut target, it should be 75 percent -- a figure many environmental campaign groups and some politicians support. Scientists say that global average temperatures will rise by between 1.8 and 4.0 degrees Celsius by the end of the century due to burning fossil fuels for power and transport, causing floods and famines and putting millions of lives at risk.