It is very likely that significant man-made climate change is underway. But the trend is superimposed on natural fluctuations, leading to regular debate on whether a particular ‘extreme weather event’ was ‘human-induced’ or ‘natural’. The widespread misunderstanding of the status of ‘scientific evidence’ makes an informed debate very difficult.
UK official weather records appear to suggest a warming of 1 deg K in the past 80-85 years. On the chart below for Ross-on-Wye, one perhaps gets a better fit for the hypothesis of a steady mean annual temperature from the 1930s to the 1960s and a rise for the subsequent 50 years.
But all scientific work, including climate science, is a matter of probabilities, not certainties. If we wait until we are 99.99% sure that we are responsible for the observed changes, this would be a recipe for indefinite delay. On the basis of the balance of probabilities, many scientists have been advising action on CO2 since the late 1980s or early 1990s.
Arguably, the key point is that energy efficiency should be taken very seriously regardless of the exact details and pace of climate change. We are not running out of energy supplies, but we are undoubtedly running out of affordable and high-grade energy.
The ‘easy’ oil and natural gas in the earth’s crust has already been discovered and consumed. The remaining fuels are more difficult and so more costly to extract.
The bulk of the energy efficiency measures in this house are more economical than renewables or fossil fuels. Irrespective of climate change, investment in this area makes good sense, assuming that money matters to us.
Mean monthly temperature,
from 1931 to 2013.