US President Barack Obama will propose a $US1 billion ($A1.1 billion) fund to mitigate the impact of climate change, as he inspects farmland parched by drought in California.
He will propose the investment in his 2015 budget that will be released next month - though it is unclear whether the fund has much prospect of advancing past Republicans on Capitol Hill.
"We've always had heat waves, but now the worst ones are longer, and they're hotter," said White House spokesman Jay Carney.
"We've always had droughts, but the worst ones are getting longer and drier.
"We've always had severe storms, but instead of hundred-year storms that happen once a hundred years, we're having hundred-year storms that happen every other year or every five years."
The new Climate Resilience Fund is intended to finance research into better understanding of projected impacts of climate change and how to better protect communities and infrastructure.
It is also designed to help vulnerable communities plan and prepare for the impacts of climate change and to encourage local measures to reduce future risk and to fund new resilient technologies and infrastructure to combat a warming climate.
Obama will travel to Fresno, for a roundtable discussion with farmers on the drought which has turned parts of the state's lush farmland into a Dust-bowl type moonscape.
Around 90 per cent of California is reported to be experiencing severe to exceptional drought.
The drought emergency has also sparked wildfires and prompted Governor Jerry Brown to ask Californians to cut their water use by 20 per cent.
Obama will pledge to implement $US100 million in livestock disaster assistance for California producers contained in a recently passed agriculture bill.
He will also highlight $US15 million in conservation funding for extreme drought areas in California, Texas, Oklahoma, Nebraska, Colorado and New Mexico.
A further $US5 million will be provided for emergency watershed protection for California, among other measures which also include a mandate for federal facilities to use less water.
