New Delhi, Oct 31 (IANS): Climate warming is impacting the human health globally. In India alone, opting out of rural labour workforce with reductions in work capacity from heat stress was the highest in the world last year, international researchers said on Tuesday.

They also foresee a striking spike in dengue outbreaks with climate change.

An average 5.3 per cent fall in rural labour capacity and thus productivity estimated globally since 2000 as a result of rising temperatures, said their study published in medical journal The Lancet.

The fall in productivity effectively took more than 920,000 people globally out of the workforce last year, with 418,000 of them in India alone.

Higher temperatures pose profound threats to occupational health and labour productivity, particularly for people undertaking manual, outdoor labour in hot areas.

The 50-page report, released just ahead of the UN COP-23 climate change conference in Bonn, shows that climate change is already a significant public health issue and a looming global health emergency.

Its findings demonstrate the various ways climate change is already affecting the health of people across the planet.

Doctors, academics and policy professionals from 24 partner organisations have contributed analysis and jointly authored the report.

As members of The Lancet Countdown: Tracking Progress on Health and Climate Change, partners behind the research include the World Bank, World Health Organization (WHO), University College London and Tsinghua University, among others.

According to the report, between 2000 and 2016 the number of people exposed to heatwave events has increased by approximately 125 million, with a record 175 million people exposed to heatwaves in 2015.

This supports the Lancet's existing research showing just under one billion additional heatwaves exposure events happening by 2050.

Undernutrition is identified as the largest health impact of climate change in the 21st century.

Related impacts of climate change on crop production referenced in the report include a six per cent decline in global wheat yields and 10 per cent fall in rice yields for each additional one degree Celsius rise in global temperature.

It documented over 803,000 premature and avoidable deaths in 2015 as a result of air pollution across 21 Asian countries, attributable to just one type of air pollution from coal power, transport and use of fossil fuels in the home.

A striking increase of three per cent and 5.9 per cent in the vectorial capacity for the transmission of dengue due to climate trends, by just two types of mosquito since 1990.

With 50 to 100 million infections of dengue estimated to occur each year, this will exacerbate the spread of the world's most rapidly expanding disease.

Favouring to tread a strong renewable energy path, the report warns that India has also seen substantial growth in coal use, with the share of coal in total primary energy supply increasing from 31 per cent in 1990 to 46 per cent in 2015.

China and India have similar shares of electricity generated by coal, at about 75 per cent of the total electricity generation.

"Climate change is happening and it's a health issue today for millions worldwide. The outlook is challenging, but we still have an opportunity to turn a looming medical emergency into the most significant advance for public health this century," an official statement quoting Anthony Costello, Co-Chair of the Lancet Countdown and a Director at the WHO.

The report 'From 25 years of inaction to a global transformation for public health', identifies health challenges the people are only just beginning to see emerge with the findings demonstrating there is no room for complacency.

Unavoidable increases in global temperature and the role of climate change as a threat multiplier and an accelerant of instability, means many trends identified are expected to significantly worsen.

Chair of the Lancet Countdown's High-Level Advisory Board and former Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC) Christiana Figueres added: "Most countries did not embrace these opportunities when they developed their climate plans for the Paris Agreement."

Under the 2015 Paris Agreement, 197 countries agreed to cut emissions in a bid to keep the global average rise in temperatures below two degrees Celsius.