2015 made history with record heat, weather extremes: WMO

In addition to mitigation, it is essential to strengthen climate change adaptation by investing in disaster early warning systems, as well as climate services like drought, flood and heat-health management tools, stressed Taalas.

Key findings of Statement on Status of Climate in 2015
Sea surface temperatures and ocean heat

Large areas of the oceans saw significant warmth. In particular, the tropical central and eastern Pacific was much warmer than average because of El Niño. Global ocean heat content was record high through both the upper 700 m and 2 000 m levels. Increased ocean heat content accounts for about 40 percent of the observed global seal level increase over the past sixty years and is expected to make a similar contribution to future sea-level rise. Sea level, as measured by satellites and traditional tide gauges was the highest ever recorded.

Arctic Sea ice
The daily maximum extent of Arctic sea ice on 25 February 2015 was the lowest on record (this record was beaten in 2016), and the minimum Arctic sea-ice extent on 11 September was the fourth lowest.

Many countries saw intense heatwaves. The most devastating ones in terms of human impact were in India and Pakistan. Asia, as a continent, had its hottest year on record, as did South America.

Western and Central Europe recorded an exceptionally long heatwave, with temperature crossing or approaching 40°C in several places. Several new temperature records were broken (Germany 40.3°C, Spain 42.6°C, U.K. 36.7°C).

North-West United States and Western Canada suffered from a record wildfire season, with more than two million hectares were burned during summer in Alaska alone.

Heavy rainfall
Global precipitation in 2015 was close to the long-term average. But within this overall figure, there were many cases of extreme rainfall, with 24-hour totals exceeding the normal monthly mean.

For instance, in Africa, Malawi suffered its worst flooding in memory in January. An active West African monsoon saw exceptional seasonal rainfall totals. The West coast of Libya received more than 90 mm of rain in twenty-four hours in September, compared to the monthly average of 8 mm. The Moroccan city of Marrakech received 35.9 mm of rain in one hour in August, more than thirteen times the monthly normal.

The powerful El Niño meant that 2015 was wet in many subtropical parts of South America (including Peru, northern Chile, Bolivia, Paraguay, southern Brazil, and northern Argentina), and in parts of the southern United States and northern Mexico.

Severe drought affected southern Africa, with 2014-2015 as the driest season since 1932-1933, with major repercussions for agricultural production and food security. El Niño induced drought exacerbated forest fires in Indonesia, impacting air quality both in Indonesia neighboring countries.

The northern part of South America suffered a severe drought including North East Brazil, Columbia, and Venezuela, hitting the agriculture, water and energy sectors. Parts of the Caribbean and Central America were also severely affected.

Tropical cyclones
Globally the number of tropical storms, cyclones and typhoons was not far from the average, but some unusual events were recorded. Tropical cyclone Pam made landfall over Vanuatu as a category five cyclone on 13 March 2015, causing widespread devastation. Patricia hit Mexico on 20 October as the strongest hurricane on record in either the Atlantic or eastern North Pacific basins, with maximum sustained wind speeds of 346 km/h. An extremely rare tropical cyclone, Chapala, made landfall in Yemen at the start of November, leading to substantial flooding. This was immediately followed by Cyclone Megh, which hit the same area.

World Meteorological Day
The WMO says that the World Meteorological Day commemorates the coming into force on 23 March 1950 of the Convention establishing the World Meteorological Organization. It showcases the contribution of National Meteorological and Hydrological Services to the safety and wellbeing of society.

The theme Hotter, Drier, Wetter. Face the Future highlights the challenges of climate change and the path towards climate-resilient societies.

The WMO adds that the increase in hot days, warm nights, and heatwaves will affect public health. These risks can be reduced by heat-health early warning systems that provide timely alerts to decision-makers, health services and the general public.

Droughts must be addressed more proactively through integrated drought management, which embraces guidance on effective policies and land management strategies and shares best practices for coping with drought.

In the event of heavy precipitation and floods, impact-based forecasts enable emergency managers to be prepared in advance. Integrated flood management is a long-term holistic approach to minimizing the risks of flooding.

“Building climate and weather resilient communities is a vital part of the global strategy for achieving sustainable development,” the WMO says. “The WMO community will continue to support countries in pursuing sustainable development and tackling climate change through the provision of the best possible science and of operational services for weather, climate, hydrology, oceans and the environment.”

— Read more in The WMO Statement on the Status of the Climate in 2015 (WMO, 2016)