A Good Night’s Sleep is Even Better than We Thought

With the demands of today’s society, people are staying up later and waking up earlier, sacrificing time spent doing something very important: sleeping.  In an article published recently in Science (Xie et al. 2013. Science 342:373-377), sleep was shown to be critical for removing waste products from the brain.  Using mice, the authors looked that the exchange of fluids between the brain and the rest of the body.  They found that while awake, there is very little fluid exchange, causing potentially toxic waste products to build up in the brain.  However when the mice were asleep, the waste products were quickly cleared from the brain.  One of the toxins that the authors looked at is implicated in many brain diseases including Alzheimer’s disease.  In fact, mice that are forced to stay awake die within days to weeks.

So what does this all mean?  It means that the perceived pressure from society to stay up all night and work all day is unhealthy.  We need sleep, that’s why our body tells us we are tired.  This article serves to emphasize how important sleep is to our brains.  Getting a good night’s sleep could be the best thing that we can do for our health – it makes us feel alert, increases our productivity, and in light of this article, may help to prevent disease.  All of these things are good for society as they lead to fewer mistakes on the job, and reduced absenteeism.  It’s time we start pressuring people to get a good sleep, not to stay up all night.  Have a good night’s sleep everyone!

Stay safe and stay informed,
Joe

Life is Evolving Right Before Our Eyes

If you are asked to describe what evolution is, it is likely that you would use some combination of: change, adaptation, natural selection, slow.  It can be very easy to think of evolution as being slow: it took a few billion years before creatures large enough to see with the naked eye evolved.  Because of this way of thinking, it was feared that living things may not be able to adapt quickly enough to climate change, since we thought that climate change was occurring more rapidly than evolution could.  Well, those of us who thought that were wrong.

Evolution can be a very rapid process.  In an article published this week in Science (Colautti and Barrett. 2013. Science 342:364-366), purple loosestrife (an invasive wetland species in North America) was found to have rapidly adapted to a more northern climate in the past 100 years.  Purple loosestrife was introduced to the United States from Europe, and in the past 100 years, it has migrated north to Ontario.  The authors had three field sites spanning from Timmins in the north to 1000 km south at Blandy Experimental Farm.  They took purple loosestrife from each location and planted them at all the others, then looked at when they flowered and the number of fruits produced.  Purple loosestrife were found to perform best at the location where they were taken from (i.e. plants from Timmins performed best when grown in Timmins compared to the other two groups).

One hundred years is not a lot of time, and given that climate has changed rapidly over this time, it is comforting to see that evolution can keep pace (even if it is an invasive species that was studied).  It may be that although the climate is changing and challenging many species, some species will evolve and adapt to new conditions – ecosystems will change.  This means that climate change might not cause as much damage to biodiversity in the long-term (some species will and are going extinct, but rapidly evolving species might be okay).

Stay safe and stay informed,
Joe

A Very Variable Future Lies Ahead

Earth’s climate is getting warmer, on average.  But what does this really mean?  The climate can vary from year to year – some years are hotter or colder than others, which can make it hard to determine how much the climate has changed.  So in a unique approach to climate projections, Mora et al. (Mora et al. 2013. Nature 502:183-187) projected when year-to-year variability in Earth’s climate would exceed the historical boundaries of global climate.  In other words, they asked the question: in which year will all subsequent years be warmer than what has been observed before 2013?  The answer to this question is called the ‘year of climate departure’, where every new year will have break current climate records.  If we look at the ‘business as usual’ scenario, the year of climate departure will be as early as 2047.  Prior to 2047 however, most years will be record-breakers.  The good news is that this is the worst-case scenario.  If everyone were to pull up their socks and reduce their carbon footprint, reduce clear-cutting of forests, and use carbon capture technologies, the year of climate departure could be pushed back by a few decades to 2069.  These predictions are considered ‘robust’ to error because the authors used 39 different climate models to obtain these results.  Each model has different assumptions, and so if you use only a single one, the prediction may be incorrect.  But if you use a lot of models, then the of all the predictions is less likely to have error due to having models that make different assumptions (and so as a whole, using all the models makes up for the individual assumptions of each model).

So what?  Why are these results alarming?  Well the year of climate departure is different for different places on the planet, and the tropics are very vulnerable (not to mention a lot of people live in the tropics).  So if we look at how many people will be affected by an altered climate, even in our best case scenario, at least one billion people will be affected by 2050 – in the worst case scenario, five billion people will be affected by 2050.  Hang on though, aren’t we expecting there to be more people in 2050 anyways?  So it might just be the same proportion of people (but there are just more of us).  Well no, those numbers are people who currently live in those areas.  This means that if we continue along and maintain the status quo, most people on the planet will be afflicted with record breaking temperatures every year!  On top of that the coral reefs, which are very sensitive ecosystems, have a year of departure of 2034 – in 20 years the coral reefs will likely look way different than they do today!

This study was a wake-up call: biodiversity and human society are threatened by climatic change, and this change is occurring faster than we previously thought.  We notice yearly differences in temperature – when we have a warm winter or cool summer – and global climate change will become very easy to feel for those of us around in 2050.  Every year will be record-breaking heat compared to now. Every. Year.

I would like to move away from those alarmist statements however with some good news.  Life evolves and adapts.  While rapid climate change may cause short-term issues (on the scale of decades to centuries), the biosphere will respond, and life will go on.  Further living things can acclimatize to new environments (within reason), which is why 5°C feels cold in the summer but warm in the winter.  So as long as we can find enough food and water, we will survive – the world will just be a different place.

Stay safe and stay informed,

Joe

Cautions on the Quality of Science

A recent article by John Bohannon in Science (Bohannon, 2013. “Who’s Afraid of Peer Review?”, Science 342:60-65) provides a cautionary tale on the quality of sources (i.e. journals) of scientific information.  John Bohannon submitted a bogus article (containing many flaws, both in the science and the logic, and was completely made up) to over 200 ‘open-access’ (meaning that the journal is available for free) journals.  These journals were supposed to be peer-reviewed: peer reviewing is a process by which other scientists read your work to ensure that your paper contains quality scientific information.  He found that over 100 journals accepted this bogus article for publication – this means that these journals thought that the science was sound (which is was not). 

This exercise was done to see where flaws exist in the publishing of scientific information in freely available publications.  It points out that while 98 journals rejected the paper, in many other journals the peer-review process failed (for many potential reasons).  But the take home message is that it is important to know where your information is coming from, and the quality of the source.  There is a reason why there are ‘big-named’ journals such as Science and Nature: it is because the top journals routinely publish high quality science and, when there has been an error (usually due to the mistake of an author), the paper is promptly removed from the scientific literature.

Especially when controversial findings are published, pay attention to what publication that information is in.  If the journal sounds or looks suspicious, check the science.  If it is not quality science, then be wary of the information contained within – it could be false.

Stay safe and stay informed,

Joe

The Difference Between Weather and Climate

All too often the definitions of weather and climate become confused.  It can be evident in everyday life, for example if it is a particularly cool summer day in July someone might remark, “climate change doesn’t seem that bad”, or if it is a warm winter, “thanks to climate change I don’t have to shovel my drive-way”, and finally a remark from a recent London Free Press article regarding climate scientists:

“…these are the same people [climate scientists] who could not tell you what the weather will be like tomorrow or next week yet they have predicted what the Earth will be experiencing for the remainder of the century”.  ‘Feel your temperature rising? Feels more like sloppy science’, London Free Press, Saturday, September 28, 2013

In this particular excerpt, the author has confounded their definitions of weather and climate, but the two are very different.  According to NASA, weather is the behaviour of the atmosphere on a short timescale of minutes to months.  Weather is very hard to predict, as it requires knowing almost every single event occurring in the atmosphere, no matter how extreme, and is influenced by the way we interact with our environment as well as natural cyclical changes in the sun’s energy output.  As a result, weather can be quite variable.  Climate on the other hand, is “the long term pattern of weather in a particular area”.  Climate is typically described on a decadal timescale, and since it is an average of weather over a  long period of time, it allows us to determine if a year was warmer, wetter, cooler, cloudier than average.  Predicting climate can be simpler than predicting weather because with climate, extreme variations in temperature and precipitation ‘average out’.  Climate models use a lot of data to inform their predictions, and as a result, their predictions will capture the average behaviour of the atmosphere over a long time period (which is what climate scientists are aiming to predict).  Climate models are not meant to predict weather, they are meant to predict long term patterns and averages in weather for a given area.  There will inevitably be years that are cooler, hotter, drier and wetter than the climate predictions, but these are just natural variations expected for a given climate.

  So sure, climate scientists cannot tell you what the weather will be like, but they can tell you what the climate will be like, and with that, you can get a good idea of whether you will be able to wear shorts more often during winters near the end of this century.  Just remember the next time someone talks about weather and climate together: weather is short-term (i.e. this week), climate is long-term (e.g. 10 years).

Stay safe and stay informed,
Joe