Growing up you believe the world is meant to be the way it is. The older I get the more I realise that this is not the case. The world is full of injustices and atrocities that governments and the voice of faith expect us to accept, though with each passing year they grow fewer and fewer, at least one would hope. I have created this blog as a space for me to rant about all things science, politics, philosophy and religion, before it’s too late and the vessel of new atheism propelled by a growing surge in secularism solves all of the world’s problems for good.

Friday, 24 June 2011

Mini ice ages and acid oceans

 "Sports on a Frozen River" by Aert van der Neer shows a typical scene. Depicted during the mini ice age (or Maunder Minimum) between 1645-1715
US solar physicists from the National Solar Observatory (NSO) and US Air Force Research Laboratory recently announced that the Earth may enter into a mini ice age within the next few decades. Scientists examined three different analyses of the Sun's recent behaviour, which all indicated that a period of unusually low solar activity, ie. 'Sun hibernation', may be just around the corner.

Solar activity is usually occurs following eleven year cycles of solar maximum where the solar activity is at its highest, to solar minimum where it is at its lowest. Dark spots on the Sun's surface known as sunspots are the result of intense magnetic activity and are therefore used as an indicator of solar activity. More sunspots = high levels magnetic activity, less/no sunspots = low levels of magnetic activity.

According to scientists we should have come out of our last solar minimum two years ago in 2009 when the eleven year cycle had come to completion. However, since then solar activity has continued to decrease (see picture below).

Decreasing trend in solar activity

The NSO wonder if this may be the next Maunder Minimum or Little Ice Age, which was a 70 year period of close to no solar activity between 1645-1715, where effectively no sun spots were recorded. During this period many European rivers, that were usually ice-free all year round, were reported to have periodically frozen over and even support ice skaters and army marches. Interestingly enough overall the Earth's average temperature had decreased by 0.4C, which just goes to show how intense small changes in the climate can be.

Red = Maunder Minimum / Little Ice Age caused by prolonged solar minimum, Blue = Usual cycle of solar maximum & solar minimum

So what does all this mean in terms of climate change and our day to day lives? Well best case scenario in my opinion is that the solar minimum ends soon and we don't go into another Little Ice Age, in which case very little or no change would occur. Worst case scenario is that we do go into a Little Ice Age and a number of negative things occur to us, and more importantly the environment.

Firstly, our Earth's average temperature has reportedly increased by about 0.4C-0.5C since the beginning of the industrial revolution. In that time a great deal of land has been gained for agricultural use, where it was once in too cold a climate to grow the right crops, it has warmed to today where they can be grown. These crops feed a great deal of the world's population. So if temperatures drop to pre-industrial revolution levels, as they would within two or three decades if the solar minimum persists, we could lose this agricultural space and face some serious problems economically.

Secondly, solar minimums represent a reduction in magnetic field strength at the Sun's surface. Unfortunately for us, a drop in the Sun's magnetic field correlates with a drop in ultra violet light (UV) emission from the Sun. Our ozone is created when UV radiation hits oxygen molecules in the atmosphere. So less UV radiation = thinner ozone layer, which funnily enough allows a higher proportion of UV light through the atmosphere than when at normal levels from the sun. Higher exposure to UV radiation is bad bad bad for all living organisms including us (it destroys DNA, our very building blocks).

Thirdly, if we see a sudden decrease in the average temperatures of the Earth, then the average sea surface temperatures will also decrease. This normally wouldn't be a big deal, but the problem is that we currently have a great deal more CO2 in the atmosphere than is naturally occurring (today's 390ppm compared to 280ppm pre-industrial revolution). Colder water is able to absorb a greater amount of CO2 than warmer water can, so if temperatures suddenly drop we will see the oceans absorb even more CO2 out of the atmosphere and become even more acidic than it currently is. At the current rate the ocean is acidifying it is predicted that we are facing another mass extinction, so if you add an untimely Little Ice Age into the mix, this will occur even sooner. We simply can't afford to lose the amount of sea life that is currently facing extinction...

No time for political agendas...!
What I worry about most of all is that politicians are going to misinterpret and misuse the information scientists have gathered and released about the Earth possibly facing another Little Ice Age. They will undoubtedly use it to suggest we are saved from climate change and global warming, but things couldn't be more further from the truth. A cooler Earth by no means suggests a healthier one. If the temperatures do drop, we may be lulled into a false sense of security as storms would be expected to become less severe and less frequent. However, better weather in the short term will do nothing to address our issues with the anthropogenic greenhouse gases that will still be accumulating in the atmosphere. It will just be waiting to hit us even harder after this small respite that may result from the prolonged solar minimum.

It's incredibly important that we understand what is going on and do what we can to address CO2 emissions and thus prevent further damage to the Earth and its ecosystems, if for no other reason than for our own sake. Politicians and the average Joe would love to believe that we can survive just fine here on Earth without healthy forests and habitats, oceans or atmosphere, but that is nonsense. The health of our biosphere, oceans and atmosphere are all intrinsically linked and if a single one is allowed to fall into degradation the others soon follow as we have seen, and the result has a direct effect on us and every other living thing on this planet.

Anyway, I've a shitload more to say on the matter and I could go further into my concluding hippy rant but that can wait for another post on another day.

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