The Bureau of Meteorology in Australia has released its annual climate statement, for 2014. As expected, it was once again a hot year across the continent (and indeed, globally):
There is a lot of year-to-year variation driven by natural climate variability, but the running mean (10-year average) plots a relatively steady rise over the last 60+ years.
The mean continental temperature was 0.91 C above the average of the whole time series (starting in 1910, when sufficient station records were available), and that average reflects temperatures as they were in about 1980. If you look at the mean for the decade centred around 1914, it was ~1.3 C cooler than the year 2014.
Globally, the story is similar:
In this case the annual variations are more suppressed (averaging over a larger area, and including buffered oceans), but again the trend upwards is clear. Broad multi-decadal patterns are clear, and there has been some slowing of the rate of increase over the past decade.
But that is different from a decrease, with temperatures still incrementally getting hotter, as the trendline illustrates. The year 2014 is expected to be the hottest on record, or close to it.
Much of the additional energy being trapped at the Earth’s surface by increased greenhouse gases is being absorbed by the oceans, sometimes referred to as the ‘flywheel’ of the climate system due to the capacity of large bodies of water to store (and then gradually release) heat. Here is the plot of the trend in sea-surface temperatures off the coast of Australia:
This heating of the oceans, along with land-based ice melt, is contributing to an ongoing trend in rising sea levels; perhaps the ‘best’ (i.e., most integrated and smoothed) metric of the Earth’s planetary energy imbalance:
And here is a ‘zoom in’ on the most recent decades of satellite monitoring data of sea level:
Here are some key summary points of climate records for Australia in 2014:
The message is clear. We need to act now to mitigate and eventually reverse these upwards trends. The key target involves around finding effective ways to replace fossil fuels with zero-carbon alternatives. That’s the focus of this blog… but it’s worth occasionally reminding ourselves of the extent of the problem we face.