Car manufacturers have been cleared in a court case fighting for compensation for alleged damage caused by cars’s CO2 emissions.

The case, brought by California’s state government, has been dismissed by a US federal judge.

California demanded millions of dollars in compensation from General Motors, Ford, Honda, Toyota, Chrysler and Nissan.

But the judge ruled that the issue of whether carmarkers were accountable was a political, not legal, matter.

State officials said they may appeal. California wanted to make the carmakers liable for the damage it said was caused by greenhouse gas emissions from the state's 32m registered vehicles.

It claimed that the manufacturers created a "public nuisance" by making "millions of vehicles that collectively emit massive quantities of carbon dioxide".

The complaint added that human-induced climate change had resulted in a range of environmental impacts across the state, including reducing the state's snow pack, rising sea levels, and increased ozone pollution in urban areas.

But the judge said a ruling was possible only if a definition was available as to what volume of greenhouse gas emissions would be deemed "unreasonable".