Rich countries are violating the human rights of millions of the world's poorest people by failing to tackle global warming, causing more people to starve, lose their homes and struggle to find clean water, a report released Tuesday says.

"Climate change was first seen as a scientific problem, then an economic one. Now we must also see it as a matter of international justice," said Kate Raworth, who authored the report by Oxfam International.

In the report, the aid agency pushes for countries to be held legally accountable for the "devastating effects of more frequent and severe climatic events" on people around the world.

The report, titled "Climate wrongs and human rights: Putting people at the heart of climate-change policy," says greenhouse gas emissions primarily produced by industrialized nations are creating floods, droughts, hurricanes, rising sea levels and seasonal unpredictability.

As a result, people's homes are being destroyed, clean water is becoming increasingly scarce and harvests are being ruined, violating the rights of millions of the world's poorest to life, security, food, health and shelter.

Citing the Inter-governmental Panel on Climate Change (IPCC), the report says climate change could:

• Halve yields from rain-fed crops in Africa as early as 2020.
• Put 50 million more people at risk of hunger.
• Cause up to one billion people to face water shortages in Asia by 2050 as glaciers melt.

The report says 23 countries — including the U.S., Canada, Australia and Japan —are home to 14 per cent of the population, but produce 40 per cent of the annual carbon emissions.

It says many of these countries failed to act on promises to reduce their emissions and instead saw them rise more than 10 per cent above 1990 levels.

The report calls for global emissions to fall at least 80 per cent below 1990 levels by 2050 and urges rich countries to fork over $50 billion a year to help developing countries reduce greenhouse gas emissions.

The report says it's "appalling" that countries try to frame climate change in economic terms, such as citing the financial costs of cutting emissions.

"Human rights principles show there can be no such trade-off," said Robert Fox, executive director of Oxfam Canada.

He urged voters in Canada's election to beware when candidates talk of "trading-off the economic and human costs of tackling climate change."

The report cites international human rights law as declaring that, "In no case may a people be deprived of its own means of subsistence."

Oxfam acknowledges that taking rich countries to court over global warming presents a "tough challenge." Not only is there no legal venue for alleged victims to present their case, lawyers would also have difficulties getting a court to recognize future injury or joint liability of the rich nations.

Oxfam has staff and partners working in more than 100 countries. The agency plans to submit the 34-page report to the United Nations High Commissioner for Human Rights, which is scheduled to release a study on the relationship between human rights and climate change by March 2009.