A team of researchers in a recent study found that global warming caused due to human activities have worsened the California's extreme four-year drought by nearly 25%.

The study conducted by Columbia University's Lamont-Doherty Earth Observatory suggests that within the span of few decades, the recurrently rising temperature and loss of moisture will drag California into even a far more persistent drought.

As per experts, the current drought, which scientists call as the worst on record, sparking wildfires and devastating the state's agricultural sector are caused due to natural weather variations.

But as per the study published on August 20 in Geophysical Research Letters, rising temperatures, which have risen in step with building fossil-fuel emissions, are making the present conditions even worse by driving moisture from plants and soil into the air.

Lead author A Park Williams, a bioclimatologist at Columbia, said, "A lot of people think that the amount of rain that falls out the sky is only thing that matters. But warming changes the baseline amount of water that's available to us, because it sends water back into the sky".

Williams told Al Jazeera that rising temperatures suggest that we need to have more and more rain to bring the situation to a breakeven point. Each raindrop and every snowflake is a little less valuable, he said.

Furthermore, he said, presently the rain is expected to resume as early as this winter, but with time, precipitation will be less able to make up for the intensified warmth.

Experts said the Columbia study provides a fresh scientific support to political leaders, including President Barack Obama and Gov. Jerry Brown, who have cited human emissions and the resulting global warming as a substantial factor in the drought.