2011 - A Year of Extremes, and More To Come...

Firstly, I hope you all had a great Christmas! It is this time of year that makes you really grateful for just the basic things in life. We are now fast approaching 2012 and is a good time to reflect on the past 12 months.

I don't think anyone can doubt that 2011 has had it's fair share of extreme weather events. December has seen the devastating monsoon in the Philippines that killed over 700, Scotland battered by a storm with wind speeds in excess of 165mph, whilst flooding in Kenya displaced thousands. November saw a mounting death toll in Cambodia after thousands were left stranded after monsoon conditions. In October residents fled Bangkok as flooding threatened to overwhelm the capital at the time when Texas was facing a dust cloud 8,000ft high, and the UK was facing it's highest October temperatures on record.  There was also the freak snow storm along the US east coast which killed 11 and left millions without power, only two weeks after hurricane Irene had ripped through the Caribbean and the south-east. September had seen even more destruction for Texas in which huge wildfires destroyed hundreds of homes. Going back to May, the world witnessed one of the most extraordinary tornado sequences ever caught on camera with more than 165 in just 24 hours in the Missouri area. March saw the most devastating natural event of the year in which Japan was hit by a double tsunami leading to 20,000 deaths and millions of pounds of damage. Cyclone Yasi has long been forgotten, but struck the Australian coast only back in February, tearing roofs of houses and bringing power lines to the ground. Going right back to the beginning of the year, January saw 400 killed as a result of torrential rain and mudslides in Brazil, there was flooding in Sri Lanka which forced 300,000 from their homes, as well as flash floods in Queensland.

Climate change sceptics may suggest that we are just becoming more 'aware' of extreme events since the 'global warming' hype of the 1980s but from research over the past few months, and the experience of extreme weather events in my lifetime I can only come to the one conclusion that anthropogenic climate change is a primary driving factor in the increasing frequency of these extreme events.

An extract from the Scientific American, dating back to June, summarises this nicely through the results of one of the worlds largest insurance companies Munich Re. The company has compiled the world's most comprehensive database of natural disasters, reaching all the way back to the eruption of Mount Vesuvius in A.D. 79. The records are kept with extreme interest by financial companies, in order to successfully evaluate insurance risks. On average 700-1000 natural disasters are added to the database each year. Their data shows a small increase in geologic events such as earthquakes since the 1980s, largely down to better reporting. However, increases in the number of climate disasters is 'far larger'. 

Peter Höppe, head of Munich Re's Geo Risks Research/Corporate Climate Centre:

 "Our figures indicate a trend towards an increase in extreme weather events that can only be fully explained by climate change... It's as if the weather machine had changed up a gear."

In the latest SREX report, we have seen the IPCC state:

"There is evidence that some extremes have changed as a result of anthropogenic influences, including increases in atmospheric concentrations of greenhouse gases."

Direct cause and effect literature has been hard to come by in the past, but this year has seen a significant increase not only in literature suggesting increasing likeliness of climate change on extreme events, but also as direct attribution. This does not mean however that every extreme event is a direct result of anthropogenic climate change. For example, solar forcing causing winter lows which I looked at in a previous post, can be assigned to natural variability. There has always been extreme events, and always will be as a result of natural variability, but the latest findings point to both an intensification and frequency of such events as a result of human impact. Over time with better climate model simulations, greater understanding of the hydrological cycle (specifically with vorticity and wind speed), and an increase in data collaboration and research papers, will I'm sure, only pile on greater evidence that extreme weather is slowly becoming the new normal (unless human anthropogenic impact is significantly minimised or reduced).

All I can conclude with is a warning: Extreme Weather Ahead.

Signing off for 2011.

2011 US Precipitation Record

It's getting to the time of year, where we can look back on events of the last 12 months and make comparisons to previous years on record. Thanks to the NOAA National Weather Service page you can create and plot precipitation maps and compare to yearly means with relative ease. I was able to create this image below within a few seconds, and if you have some time, why not try it out yourself:

The image displays 2011 mean precipitation (in mm) as departure from normal across the US. There are two key things to note: firstly, the extremely high rates of precipitation in the north-east US, and secondly, the extremely low-rates of precipitation in the south (500mm above and 500mm below respectively). I have touched on precipitation extremes in previous posts, but Philadelphia is now the wettest it's been since 1867 and there are 20 other cities who have broken long-term records or are close to. The increase in precipitation in 2011 has largely been down to the tornado outbreak in April/May combined with hurricane Irene and other heavy summer thunderstorm rains.

Now the heavy rains are only half the picture, sections of 16 states have precipitation rates 500mm below normal this year. It has been a significant year of contrast with many places being washed away with heavy rain and floods or whilst other areas have faced and suffered from significant dry conditions.

I have yet to really touch upon droughts in any of my posts, and now would probably be a good time to do so. Arnell (who's based at the Walker Institute for Climate System Research in Reading) in 2004 published this paper on climate change and drought, which has been recently built upon in the SREX report. Essentially droughts are likely to become more frequent and intensify with the intensification in the hydrological system. Precipitation in large parts of southern Europe, north Africa, central Asia and southern Africa (which are often subject to frequent dry conditions), are likely to experience even less rainfall, increasing drought risk. Moreover, the climate change risk is super-imposed on top of things such as land cover changes which could exacerbate the problem even further. It is well agreed upon that there will be an increased (physical) drought risk, but there is still considerable uncertainty over the magnitude of this change. 

The variability in climate change and precipitation is also displayed in a study released last month in which regional climate models were developed for Cyprus in order to project weather extremes. Despite, increases in temperature across the entire country (of 1-2 degrees Celsius in both summer and winter), some areas are expected to experience less frequent precipitation events of lower magnitude (inland places such as Nicosia) whilst other areas such as Saittas and Limassol may experience more precipitation events, with increased rainfall.

Climate change science predicts that if the Earth continues to warm as expected, wet areas will tend to get wetter, and dry areas will tend to get drier. Therefore you would expect this year's side-by-side extremes of very wet and very dry conditions in the US should become increasingly common in the coming decades. 

Is Strange Weather in the Air or just On Air?

I came across this clip from NBC news last week which is probably one of the most one-sided reports on climate change causing extreme weather I've seen in recent weeks. It doesn't even try to balance the argument, or even suggest "on the other hand", which is surprising for a major US news network. It devotes a full 2 and a half minutes to suggesting that extreme weather events will become more likely and are a result of climate change. The video concludes by saying "today, no one can deny that extreme weather is here to stay"!

After doing a bit of digging in some journal archives, I came across this interesting paper. It looks at how extreme weather event coverage on US national television has changed over the past 50 years, and assesses whether news coverage can be used almost as a proxy as to whether extreme events are becoming more discernible.

News archives between 1968 and 1996 were used to track records of heat waves, droughts, hurricanes and floods from ABC, CBS and NBC television networks. A control period was used in order to distinguish between 'climate science' and 'global warming' frenzies that hit news and media in the late 80s. Some of the key findings are displayed on the graphs below:

Annual coverage of heat waves on the network news.

Annual coverage of floods on the network news.

Annual coverage of hurricanes on the network news.

The results show a dramatic increase in the coverage of floods and hurricanes since the 1980s, however, it must be noted that the different types of extreme events do not receive equal coverage: for example, annual peaks for droughts contain about twice as many stories as the peaks for heat waves. 

One of the key findings that the data revealed is that surprisingly there is no association between coverage of climate change and the overall coverage of extreme events. They also discovered that whilst total news coverage of extreme events in the US increases dramatically, coverage devoted to extreme events in other countries remains relatively constant (see image below).

Index of extreme weather coverage on the network news by all events and foreign events.

There are a variety of limitations with using a study such as this to show extreme events are linked to anthropogenic change. Media is always subjective and some news stories can be made at the expense of others. Some stories can often dominate the news, whilst others get left behind. Changes in technology, forecasting and the ability to track extreme weather events has also come a long way in the last 50 years and the ability to cover events and show footage will impact whether an event is covered.

Despite not a lot of concrete evidence coming out of reports such as these, it is pleasing that researchers are trying new and innovative ways of collating evidence for climate change.

Coincidence or Causality?

New to the blogging world, I will keep my fist post short and sweet, a flavour of what's to come, if you will.Why start my blog with this video? Well, quite simply because it is a video that answers absolutely nothing. 

The video does however make you think by asking a lot of questions. After personally experiencing a blistering, record breaking 29.4 degrees Celsius in the UK on the 2nd October, it is not uncommon to create a logical connection between climate change and these extreme weather conditions. Is there a much bigger link to it all, or are they just freak anomalies? 

This blog will flirt around with thoughts, news stories and academic debates in an attempt to answer questions surrounding extreme weather conditions and climate change. What lies ahead in the future? Are there any indicators of similar patterns of extreme weather events in the past? Or is this all just one big coincidence? 

“There have been tornadoes before, and floods — that’s the important thing. Just be careful to make sure you don’t let yourself wonder why all these record-breaking events are happening in such proximity — that is, why there have been unprecedented megafloods in Australia, New Zealand and Pakistan in the past year. Why it’s just now that the Arctic has melted for the first time in thousands of years. No, better to focus on the immediate casualties, watch the videotape from the store cameras as the shelves are blown over…” Bill McKibben 350.org

So I will leave you with this initial thought to ponder, are extreme weather events and climate change coincidence or is there some form of causality?