CNN  — 

Climate change is here and affecting our health, with extreme heat in particular also having effects on productivity, food supply and disease transmission, a new global report finds.

More people than ever are vulnerable to heat exposure globally, and numbers are rising, according to The Lancet Countdown on Health and Climate Change report by an international group of researchers, published Wednesday.

It comes just days after climate reports from the US government and the United Nations said that greater action on climate change is needed, with the UN report showing that in 2017, the highest levels of carbon were emitted globally.

Older people in Europe and the Eastern Mediterranean are most vulnerable because of larger aging and urban populations there.

The latest report estimates that 42% of over-65s in Europe and 43% in the the Eastern Mediterranean are already vulnerable to heat exposure; 38% of this group is vulnerable in Africa and 34% in Asia.

The report identified present-day changes impacting public health including lower productivity, decreased crop yields and spread of diseases such as dengue and cholera, said researchers from 27 global institutions, including universities and research centers, and the UN who put together the study.

Present changes in heat waves and labor capacity “provide an early warning of the compounded and overwhelming impact on public health that is expected if temperatures continue to rise,” said Hilary Graham, professor of health sciences at the University of York in the UK, who participated in the report.