The WMO Statement on the Status of the Climate in 2015 was released on 23 March. In short, the world continues to warm, the seas continue to rise, and the weather becomes hotter, wetter and drier, with continued extreme conditions.
There were reports on ABC RN’s The World Today and at Climate Central, but the best I found with images that go beyond the report was on our ABC. I’ll pick out some of the elements that interested me.
We know that the temperature went through the roof in 2015, easily beating previous records. This graph, referenced to the 1961-1990 average, identifies the years influenced by El Niño and La Niña:
The graph represents the average of the three main global temperature datasets.
More than 90% of additional heat from climate change ends up in the oceans. The following graph shows the ocean heat content change for the top 700 metres, and the top 2000 metres since 2005:
I believe about 40% of sea level rise comes from thermal expansion, so the uptick in the last couple of years makes sense.
This image shows broadly where it was wetter and drier:
In some parts it was very wet, with weather that can only be described as erratic.
For example, despite near average rain for the year in Niger one 24-hour flooding episode killed 25 people. In Tanzania 50 died. For South Africa 2015 was the driest on record.
In Pakistan 90% of the seasonal total was concentrated over the first half of the season in areas which the rain seldom reaches. During March and April there was unseasonal weather, with heavy rain and late frost damaging crops. A rare tornado hit the Peshawar valley on 27 April and killed 45 people.
Yemen had the first cyclone ever to make landfall.
It was exceptionally hot in India, Pakistan and Iran, with temperatures over 45°C. This image shows the maximum temperatures for 24-30 May 2015:
About 2500 people died due to the heat. In Pakistan from 17 to 24 June more than 1400 people died in the heat in Karachi and about 200 people in other parts of Sindh province.
Extreme heat is common in the pre-monsoon season on the Indian subcontinent, but the heat extended over a larger area than normal and was accompanied by exceptional humidity.
Argentina had its coldest October on record in a year that was the second warmest on record.
And so it goes. Europe’s summer was exceptionally warm. This image shows the average number of days exceeding the 90th percentile for the reference period 1981-2100, which in itself is a warm period:
Levels of CO2 in the atmosphere continue to rise, as does the rate of increase:
Preliminary NOAA data for 2015 indicate that the CO2 increase of 3.01 ppm/year was a record.
Methane and nitrous oxide give no cause for comfort:
In Australia the biggest distinguishing feature was the heat in October, which was a record and the biggest monthly anomaly, in a year which was only the fifth hottest.
People tend to think of the oxone layer problem as being fixed. While the use of halons and chlorofluorocarbons has been discontinued, they will persist in the atmosphere for many decades. The oxone hole still appears and depends on the meteorological conditions. 2015 was not a good year:
At the other end of the globe, Alaska had record wildfires and in Greenland they recorded the equal record low of –55.2°C.
I’ll finish with the message from the WMO Secretary-General:
- “Today the Earth is already 1°C hotter than at the start of the twentieth century. We are halfway to the critical 2°C threshold. National climate change plans adopted so far may not be enough to avoid a temperature rise of 3°C, but we can avert the worst-case scenarios with urgent and far-reaching measures to cut carbon dioxide emissions,” WMO Secretary-General Petteri Taalas said.
“Our planet is sending a powerful message to world leaders to sign and implement the Paris Agreement on climate change and cut greenhouse gases now before we pass the point of no return,” he said.
There’s a lot of difference between signing and implementing.