2015 – hottest year on record

From Shreerupa Mitra-Jha
Geneva

The year 2015 was the hottest on record by a “strikingly” wide margin, the UN climate agency said today, attributing it to strong El Nino combined with human-induced global warming that resulted in extreme weather events globally, including in India.

“Fifteen of the 16 hottest years on record have all been this century, with 2015 being significantly warmer than the record-level temperatures seen in 2014. Underlining the long-term trend, 2011-15 is the warmest five-year period on record,” the World Meteorological Organisation (WMO) said.

In 2015, temperatures were 0.76 Celsius above the 1961-1990 average– the internationally agreed base period for measuring long-term climate change. The average global temperature during the baseline period was 14 C.

The record temperatures over both land and the ocean surface in 2015 were accompanied by many extreme weather events globally such as heatwaves, flooding and severe drought, including in India, Pakistan, Paraguay, the UK, the US, Australia, South Africa.

“We have reached for the first time the threshold of 1 C above pre-industrial temperatures. It is a sobering moment in the history of our planet,” said WMO Secretary-General Petteri Taalas.

Last year, 10 out of 12 months had recorded the highest temperature for the respective months ever since record keeping started 136 years back.

“Climate change will have increasingly negative impacts for at least the next five decades. This emphasizes the need to invest in adaptation besides mitigation.

“It is important to strengthen the capability of countries to provide better disaster early warnings to minimize human and economic losses. Climate change increases the risk of weather-related disasters which are an obstacle to sustainable development,” Taalas added.

An exceptionally strong El Nino combined with human-induced global warming caused the record-high temperatures last year.

El Nino is an abnormal weather pattern that is caused by the warming of the Pacific Ocean near the equator. This warm water displaces the cooler water that is normally found near the surface of the eastern Pacific, setting off atmospheric changes that affect weather patterns in many parts of the world.

A 3-month average temperature increase of least 0.9 F (0.5 C) needs to occur in the waters of the eastern Pacific Ocean near the equator for it to be considered an El Nino year.

“Now it is slowly declining but it is still [a] very strong El Nino. And the expectation is that by, maybe, mid-Spring, it will come to a neutral state that is neither warm nor cold,” Rupa Kumar Kolli, chief of the World Climate Applications and Services Division and an El Nino expert at the WMO, told PTI.

However, the WHO has warned that even though the current El Nino event is expected to peak this month but the adverse health impacts are likely to worsen and affect 60 million people globally.

The UN health agency has warned against cholera epidemics, vector-borne disease outbreaks like dengue and malaria, respiratory infections, increased levels of malnutrition and damage to health facilities, among other adverse health impacts, caused by droughts and flooding.

The consolidated WMO analysis considered to be one of the most authoritative international reference source — collates data from three internationally-renowned observational datasets maintained by the Hadley Centre of the UK’s Met Office and the Climatic Research Unit, University of East Anglia, United Kingdom (HadCRUT4); the US National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information; and the Goddard Institute of Space Studies (GISS) operated by the National Aeronautics and Space Administration (NASA).

WMO also takes data from the re-analyses produced by the European Centre for Medium-Range Weather Forecasts.

PTI