The last post in this series on climate change explored the dynamics behind the greenhouse effect. This post is all about the evidence that the planets climate is changing.
Temperature
Detailed temperature records of sea-level surface temperature and marine air temperature show from 1880-2012 there has been a 0.85 degree C rise in global surface temperature. Although this may not sound like much, the next post will show just how significant small long-term temperature changes can be.
Precipitation
Although the records are not as extensive as temperature records, in the last 30 years there has been a significant increase in global precipitation levels. Regionally, in eastern N.America and N. Europe, significant increases in precipitation have occurred (although there may be seasonal trends too in these regions with winters becoming wetter and summers becoming drier). Furthermore, in some traditionally arid regions such as the Sahel, the climate has become even drier, resulting in increased drought, and humanitarian disasters.
Sea level
IPPC reports state between 1901-2010 the global sea level has risen by 17-21 cm. This has been caused by the melting of glaciers and the Antarctic and Greenland ice sheets, the thermal expansion of water, and land water storage release.
Polar ice
The polar ice sheet has decreased between 1979-2012 by 0.45-0.51 million km². This is greater than the increases seen in the Antarctic sea ice sheet which has grown by around 0.20 km² per decade due to cooler air and water distribution changes, demonstrating trends are not universal.
Weather patterns
Recent weather patterns have shown substantial changes, evidenced by increased flooding in England (at least 3 one in 20 year floods within 13 years between 2000-2013) and China among other regions. Furthermore warmer spring temperatures are occurring earlier in the year in Britain, evidenced by flowers blooming earlier each year and birds nesting around 12 days earlier than 38 years ago. Finally heat wave events are occurring in Europe more frequently which has lead to human deaths.
The cause for most of these changes is likely to be the exacerbated greenhouse effect. However, sceptics argue against this, which will be the topic of a future post.
The next post in this series will be the effects of climate change on God’s creation, both people and wildlife.
Sources
Maslin, M. (2014) Climate Change A Very Short Introduction. Oxford University press.
https://www.nasa.gov/content/goddard/antarctic-sea-ice-reaches-new-record-maximum
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