When the UK Climate Projections 2009 (UKCP09) were released, I was really keen to understand them and work out what changes they predicted for my home town of Reading. Following this through in detail, I dig into the spatial and seasonal differences we can expect. As well what is underneath these big shifts in long term average temperature, rainfall, etc.
What climate change am I interested in? 1 January 2010
To understand how climate change is going to effect me, I need to be clear to define: where (Reading, UK) and when (March & August, 2050 & 2080); and which future emission scenarios (the highest & lowest) I am interested in. Fortunately I will then be able to use the new UK climate projections to give me some detailed data on how big these changes are likely to be…and I need to be clear about what I mean by the word “likely” (the middle, 67% probability band).
Temperature changes in MarchThis is an in-depth look at how the UK climate projections (2009) can be used to understand how climate change will effect temperatures, for me, in the month of March. I introduce you to some real temperature data from the University of Reading Atmospheric Observatory, to help visualise what day-to-day temperatures might be like. And it seems likely that, even by the 2050s, and even under lower emission scenarios, we will see March temperatures that are more like the averages that we are used to seeing for April.
Temperature changes in AugustEven by 2050 we could experience heat waves, with hottest day temperatures that reach 40ºC in the shade. By the 2080s there is a big difference in the temperatures that we are likely to see by following the high, rather than the low scenario. It looks like it could get uncomfortably hot compared to what we’ve been used to.
Seasonal climate changes in 2050s Reading
There is a significant amount of difference expected between the individual seasons, which you cannot understand from the crude estimates of change to average annual temperature. In Reading, we will see summer temperatures increasing more relative to the rest of the year, although it will be milder in all seasons. It looks like winter will be wetter and summer will be drier: there is more uncertainty about how rainfall will change for spring and autumn.
The table is explained in more detail in the following post…
Seasonal climate changes in 2050s Reading
There is a significant amount of difference expected between the individual seasons, which you cannot understand from the crude estimates of change to average annual temperature. In Reading, we will see summer temperatures increasing more relative to the rest of the year, although it will be milder in all seasons. It looks like winter will be wetter and summer will be drier: there is more uncertainty about how rainfall will change for spring and autumn.
Seasonal comparisons
Spring (March – May) – looks like it will be warmer, with a bit less cloud and lower humidity. There is uncertainty as to whether rainfall amounts are likely to change to be drier or wetter.
Summer (June-August) – will be hotter, with temperatures increasing relatively more in this season than at other times of the year. Notice that day & night temperatures look like they increase more in the earlier summer months than we saw in the detailed analysis of August temperature changes. There is a notable reduction in the amount of cloud and expected humidity levels. It also looks likely that it will be significantly drier on average (the low scenario predicts 73% chance that it will be drier); more research will need to be done to see if there are changes to extremes.
Autumn (September-November) – seems to change in a similar way to the Spring. There does appear to be slightly wider uncertainty bands for many of the climate variables, and it looks like there is a higher chance that it will be wetter in the future rather than drier.
Winter (December-February) – will be milder, more research will need to be done to check that cold snaps are less frequent and / or less extreme (I would expect so). Whist cloud and humidity look like they will remain similar to what we are used to, there is a very noticeable expectation of that we will see more rainfall. Further research will need to be done to check whether future rainfall events are expected to be more extreme, and / or more prolonged.
Central England Temperature and Climate Change Projections
Frost Days
IPCC Special Report 15 – Global warming of 1.5degC
Extreme Events and Climate Change presentation