NASSAPIR, Uganda - The rainmakers were convinced the god was angry.

Holding a sheep on its hind legs, a young man sank a spear into its neck. Those present drank its blood and splashed the rest around the local water catchment area in the hope of appeasing Ekipe, the rain god.

But rituals like this in Nassapir village, in northeastern Uganda's semi-arid and under-developed Karamoja region, no longer seem to pay off.

"We don't know why the god is no longer answering our requests," said Laurien Lokwareng, an elder of the Jie ethnic group. "For years, we used to ask the god for rain and we got it in abundance, but we have had four years without enough rain now, and this is very strange."

In a new report, international aid agency Oxfam says impoverished communities like Nassapir are already being hit hard by the effects of global warming, including increased drought.

And without international funding to help them cope and tough targets for cuts in greenhouse gas emissions, the food, water, health and livelihoods of hundreds of millions of the world's poorest people will be put at even greater risk.

Oxfam says interviews it carried out with farmers in 15 countries in Africa, Asia and Latin America show that seasons are shrinking in number and variety.

This is destroying harvests, pushing farmers to abandon traditional crops and causing widespread hunger - which, the agency predicts, will likely be "climate change's most savage impact on humanity in the near future".

Rainfall is reported to be more erratic, shorter and more violent. Unusual weather events - including storms, drier spells and fluctuating temperatures - are happening more often. And farmers say winds and storms have got stronger.

"We think that 'changing seasonality' may be one of the most significant impacts of climate change for poor farmers, and that is happening now," said Oxfam programme researcher John Magrath in the report.

INCREASED HUNGER

Savio Carvalho, Oxfam's climate change advisor for the developing world, told Reuters global warming was already affecting people across Africa, and would wipe out efforts to tackle poverty without urgent action like massive tree planting.

"In sub-Saharan Africa, (yields of) maize, which is a staple crop, will decrease by 15 percent by 2020 and that is a big number," he said.

"Drought is now happening on a yearly basis, and there is increased hunger and starvation because of declining food stocks, as we see here in Karamoja."

Surveying her withered maize garden, farmer Nakong Ilukal blamed the unpredictable weather.

"I have never witnessed this in the last 10 years," she said. "I will get nothing from here - this time I don't even know what to feed my family."

At home, her youngest child is ill and her family is surviving on one meal a day.

According to Uganda's health ministry, the malnutrition rate in the semi-arid region - which has experienced 14 droughts in 25 years - is 19 percent, while the U.N. World Food Programme provides food aid to at least 970,000 of Karamoja's 1.1 million people.

Livestock - which provide vital food and income for Karamoja's communities - are also at risk.

"In the last three years we have seen an increase of 30 percent in lung diseases because they spread so fast in the dry seasons," said Panvuga Pascalino, Kotido's only vet, as he immunised thousands of cattle and goats.

UNRAVELLING MYTHS

Jie rainmakers firmly believe their environment is getting warmer, and they must find answers for the dwindling rainfall and their failing crops.

"One reason, we know, is that the god of rain resides in big trees, but our people are cutting all of them down for charcoal and firewood, so he must be very angry," said Lokwareng.

Carvalho said more needed to be done to raise awareness.

"Governments need to embark on massive awareness drives so we can cut some of the myths around climate change to help people realise that this is a global phenomenon which has local impacts," he said.

Oxfam also warns that in places like Karamoja - which is already plagued by high levels of violence due to armed cattle raids between ethnic groups - failure to improve access to water is likely to exacerbate conflict.

But the report argues that the worst effects of climate change on hunger and poverty can be avoided if communities and governments start adapting now.

Oxfam is taking practical steps, building a dam in Nassapir to capture any rain that does fall for people and animals - although villagers are wary of sharing their precious resource with other communities.

"I think we should build a fence to stop the other communities from bringing their animals here to take our water, because they will finish it," said village elder Lokwareng.

Carvalho also recommended developing drought-tolerant maize seeds, and experimenting with alternative sources of energy in poor rural areas, where most people rely on cutting down trees for firewood and construction.

He said there were several possibilities in Kotido, the district that includes Nassapir.

"Poverty is compounded when people don't have access to energy, and people in places like Kotido could start exploring bio-gas from cow dung and solar energy from the abundant sunshine with a bit of investment," Carvalho said.

(Additional reporting by Megan Rowling in London)

You can read the report, Suffering the Science: Climate change, people and poverty, on Oxfam's website.

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