The fickle nature of weather patterns is ultimately responsible for the where and when of tropical rainfall extremes which wreak damage on agriculture, infrastructure and people. Tropical cyclones, such as Enawo which battered Madagascar in March, can severely impact low-lying, highly populated regions through intense rainfall combined with strong winds and storm surges. Explosive thunderstorms operating at smaller spatial scales can generate flash flooding and may lead to devastating landslides in mountainous terrain. A sustained dearth of rainfall or multiple failed seasonal rains, as implicated in drought currently impacting Somalia, Kenya and Ethiopia, are also inextricably linked with evolving weather patterns, often driven by the slower heart-beat of the oceans as they pace out the internal rhythm of El Niño Southern Oscillation and its decadal counterparts. Continue reading Changing wet and dry seasons
In the last few decades, Europe has warmed not only faster than the global average, but also faster than expected from anthropogenic greenhouse gas increases (van Oldenborgh et al., 2009). With the warming, Europe experienced record-breaking heat waves and extreme temperatures, such as the 2003 European heatwave, 2010 Russian heatwave, and 2015 European heatwave, which imposed disastrous impacts on individuals and society. Continue reading Rapid increase in heat extremes in Europe
The warming that has occurred over the past 160 years has not been the same everywhere. Certain regions, such as the Arctic, have warmed far more than the Southern Ocean for example. How well do our climate models represent these differences? Continue reading Zonal mean temperature change in observations & models
Just over a year ago I received an email from a colleague I had never met. Jan Fuglestvedt asked whether I had ever made a spiral version of my global temperature graphics. He ended by suggesting that this was ‘just a (crazy) thought’.
But, it was a Friday afternoon – what else was I going to do? Continue reading Spiral birthday
When designing scientific graphics, one key choice is about which colour scale to use (something discussed in several previous posts). The animated graphic below is a simulation of how an image would look to someone who is colour blind (a few percent of men). Continue reading Choose colour scales carefully
Inspired by National Geographic’s climate change evidence graphics, I made my own global temperature polka-dot visualisations.
In the spirit of experimentation, here are three types, successively getting more complicated. After comments from several people I have made both portrait & landscape versions. I would be interested to know which works best for you. Continue reading Global temperature change as polka-dots
The term ‘Little Ice Age’ refers to a period of cooler temperatures between around 1400 and 1850, although a range of dates are used. This climate feature has been inferred from various types of direct and indirect evidence, but it is still not clear how widespread these cooler temperatures were.
A new article by Lockwood et al explores some of the commonly used indirect evidence such as paintings and the occurrence of ‘frost fairs’ on the Thames. We also address the common assumption that the cooler temperatures were solely due to a reduction in solar activity (the Spörer and Maunder minima). Although this assumption is almost certainly wrong, the two features are sometimes considered to be synonymous.
The Committee on Science, Space & Technology of the US House of Representatives conducts regular evidence hearings on various science topics. On Wednesday 29th March, there is a hearing on “Climate science: assumptions, policy implications, and the scientific method”. The following letter, summarising the scientific findings of Fyfe et al. (2016) and Karl et al. (2015), has been submitted as evidence to this hearing.
The broader context is that the Committee Chairman, Mr. Lamar Smith, has previously discussed the findings of Fyfe et al. (of which I was a co-author), claiming: “A new peer-reviewed study, published in the journal Nature, confirms the halt in global warming”. This statement is incorrect, and motivated the clarification on what Fyfe et al. actually says.