CO2 rising almost 100 times faster than at end of the last ice age

The level of carbon dioxide is rising almost 100 times faster than at the end of the last ice age, according to the World Meteorological Organisation.

The increase in CO2 last year was "50 per cent higher than the average of the past 10 years," according to the WMO, the BBC reports.

El Nino weather patterns and human activity are the main driving force behind the earth's level of C02 being at a level not seen for 800,000 years, researchers say.

Scientists say climate change is the major health threat of the 21st century.

Climate change is already a critical public health issue - says a report published Monday in the medical journal The Lancet.

Today, 71 per cent of 2971 cities globally exceed World Health Organisation (WHO) guideline levels for particulate matter, according to the experts, CNN reports.

They believe air pollution has surged to a record high, but things are set to get worse if adequate changes aren't made. 

Data from WHO shows that air pollution causes more than three million deaths every year.

China is the worst affected country where there are over 1 million deaths each year and air pollution is also reducing the effectiveness of the nation's solar plants. 

The consequences of air pollution include increased disease, heat waves and extreme weather the consortium of experts says.