NET ZERO: Why the world is warming
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Badenoch and Strathspey is feeling the effect now of global warming.
While causes of individual events are difficult to pin down, the wider trend points clearly to global warming.
It includes the long term decline in snow, dryer summers, changing migration of birds, increase of pests such as ticks, more frequent storms and flooding.
'Climate change is already happening and a serious risk in Scotland' acknowledges NatureScot.
This article explains why the world is warming. It follows last week’s article about net zero and why it is important.
Average world temperatures today are about 1.2°C warmer than before the Industrial Revolution.
That average is for the Northern and Southern hemispheres, for winter and summer.
Until the Industrial Revolution average temperatures had changed little for the previous 11,000 years compared to the rapid increase we are seeing now.
During those thousands of years of stable climate, mankind developed agriculture, built societies and created civilisation.
We know about these temperatures in the past from direct measurement with thermometers since around 1850.
Earlier temperatures are reconstructed from good evidence, such as tree rings and ice cores from Antarctic and Greenland ice caps. Glaciers and geology add further information.
This increase in average temperatures, what is called global warming, came with us burning coal during the Industrial Revolution, from around 1850.
It accelerated from 1900 with us burning also oil and gas. July, August and September this year were the hottest recorded for those months.
Burning of these fossil fuels releases carbon dioxide (CO2) and other greenhouse gases (GHGs).
CO2 in the atmosphere had been fairly constant for the past 800,000 years, as shown in this graph.
Atmospheric CO2 has been measured directly since 1958 at a mountain observatory in Hawaii. We know about CO2 in the atmosphere before then from air bubbles in ice cores.
Why the world is warming
Global warming since the Industrial Revolution has happened with this dramatic increase in atmospheric CO2, as shown in this next graph
GHGs, such as CO2, trap some energy radiated from the sun, so that it is not reflected back into space.
With more GHGs, our atmosphere traps more energy, warming the world.
Mainstream climate scientists have shown that GHGs in the atmosphere, in particular CO2, are causing global warming (IPCC ‘AR6 Synthesis Report’, NASA ‘Vital Signs, Carbon Dioxide’, World Meteorological Organization ‘Greenhouse gases’, UK Met Office ‘Causes of Climate Change’).
To stop global warming, we must stop increasing GHGs in the atmosphere. Without that, Badenoch and Strathspey’s climate, biodiversity, people and businesses will suffer more from global warming.
We will feel also the effects of global warming elsewhere in the world as species, including pests, as well as people migrate here, and as economies are disrupted.
