An entire generation of children face the risk of falling victims to climate change if measures to cut emissions are not undertaken immediately, a study warned on Thursday.

Air pollution, extreme weather, food shortages and infectious diseases have taken a steep toll on public health, especially youngsters, according to a report in The Lancet, one of the world's most prestigious medical journals.

Health experts and scientists from 35 institutions pointed out that with the current rate of emissions, a child born today will experience a world that is more than four degrees warmer than the pre-industrial average.

The report painted a dire picture of the future, including acute temperature variations, flash floods, wildfires, mass crop failures, air and water borne diseases.

As temperatures spike, a drop in the yields of staple crops such as rice, soybean and maize are predicted, leading to malnutrition among infants.

Frequent disease outbreaks have also added to the woes of a climate-stressed planet. For instance, dengue, a mosquito-borne virus is spreading. Nine out of the 10 most hospitable years for dengue transmission have occurred since 2000.

Children would be breathing more toxic air throughout their lives, resulting in reduced lung activity, asthma and heart attacks.

According to the World Health Organization (WHO), almost seven million people die annually as a consequence of inhaling particles present in polluted air.

In 2016, premature deaths from outdoor air pollution reached 2.9 million. More than 440,000 were victims of coal emissions.

"Children are particularly vulnerable to the health risks of a changing climate. Their bodies and immune systems are still developing, leaving them more susceptible to disease and environmental pollutants," said Nick Watts, who co-led The Lancet Countdown on Health and Climate Change study.

"The damage done in early childhood is persistent and pervasive, with health consequences lasting for a lifetime.

"Without immediate action from all countries to cut greenhouse gas emissions, gains in well-being and life expectancy will be compromised, and climate change will come to define the health of an entire generation," he told a briefing in London.

The authors of the report called for urgent steps to tackle climate change and prepare global health systems for the challenges ahead.

The Paris Climate Accord aims to keep global temperatures well below two degrees, or 1.5, if possible. Experts said that, if successful, the initiative would help a child born today to experience a world with net-zero emissions, in about 30 years.

"Nothing short" of a 7.4 percent year-on-year cut in CO2 emissions until 2050 would limit global warming to 1.5 Celsius, they added.

The Lancet study comes as Australia witnesses one of its worst wildfires in living memory across the eastern seaboard and August being recorded as the hottest month ever.

A global youth movement inspired by Swedish schoolgirl Greta Thunberg, recently took to the streets, demanding decisive action against climate change.

Reacting to the findings, The Lancet's editor-in-chief Richard Horton said climate change was "one of the greatest threats to the health of humanity today".

"But the world has yet to see a response from governments," he added. "We can't afford this level of disengagement."