Climate Change Week 3

It is now time to reflect on week 3 of the Climate Change MOOC.  This week has been about the here and now.  Or at least the past 150 years rather than the events of millions and billions of years ago discussed in previous weeks.  There is no doubt that the technology that is now available and the amount of effort put into examining climatic trends, does give confidence in the expert assessments of climate change.  It is also an indisputable fact that there has been a significant rise in the Earth's temperature during the 20th century and up to the present time.  The most recent decade is the warmest on record since measurements have been taken over the past 170 years.  This has resulted in rising sea levels from thermal expansion and the melting of land ice.  It is worth noting that, contrary to some peoples' views, melting sea ice does not increase the level of the oceans because floating ice displaces the same volume of water as it would if it were liquid - Archimedes principle.  There have also been some extreme weather events - floods, heat-waves, hurricanes, etc - but apparently it's not possible to attribute a particular event to climate change because it might be due to natural fluctuations.  Interestingly, although the world is getting warmer and the Arctic ice cap is reducing in size, the Antarctic sea ice is expanding.  This paradox is explained by the influence of winds and waters in the southern oceans.

As we know, carbon dioxide is one of the key gases in the warming blanket around the planet and this week we learnt more about the carbon cycle.  10 petagrams of carbon (a petagram is 10 to the power 16 grams!) are released into the atmosphere each year as a result of human activities.  90% comes from the burning of fossil fuels and the remaining 10% from deforestation.  Out of the 10 petagrams of CO2 released each year, the atmosphere increase is about 4.5 petagrams.  The rest is absorbed by the land and the ocean.  Without this absorption, the atmospheric CO2 would be much greater and we don't really know how these carbon sinks will be affected by climate change.  I did an analysis of the emissions in metric tons per capita for the following countries:

Turkey (where I live) 4.1

UK (where I come from) 7.9

USA 17.6

China 6.2

India 1.7

The emissions from China are increasing year on year, which is hardly surprising.  China is fast becoming the manufacturing centre for the world and as an increasing global population demands more manufactured goods, China's CO2 emissions will increase.  This assumes, of course, that the increase in manufacturing capability still depends on the use of fossil fuels.

After three weeks into the course, I am now convinced that anthropogenic (I love that word even though 'human-induced' is probably more widely understood!) activities, are strongly linked to the rise in global temperatures.  What, in my view, is debatable is whether recent extreme events are natural fluctuations or exacerbated by human activity.  I have found the discussions interesting.  I do feel that some participants have very fixed views on the cause and consequences of climate change, maybe I do!  But I really am trying to keep an open mind and evaluate the material objectively in order to improve my knowledge of an issue that is so important to the future of humanity.

So onwards and upwards, roll on week 4!