The Holocene Context for Anthropogenic Global Warming
By Paul Homewood
Recent warming needs to be put into perspective against longer term climate trends. As HH Lamb and many others knew years ago, the world during most of the Holocene was much warmer than today.
Ed Hoskins has pulled together a lot of the evidence showing this, and it is well worth a bookmark.
This is his summary:
Our current beneficial, warm Holocene interglacial has been the enabler of mankind’s civilisation for the last 10,000 years. The congenial climate of the Holocene epoch spans from mankind’s earliest farming to the scientific and technological advances of the last 100 years.
However all the Northern Hemisphere Ice Core records from Greenland show:
- the last millennium 1000AD – 2000AD has been the coldest millennium of the entire Holocene interglacial.
- each of the notable high points in the Holocene temperature record, (Holocene Climate Optimum – Minoan – Roman – Medieval – Modern), have been progressively colder than the previous high point.
- for its first 7-8000 years the early Holocene, including its high point “climate optimum”, had virtually flat temperatures, an average drop of only ~0.007 °C per millennium.
- but the more recent Holocene, since a “tipping point” at ~1000BC, has seen a temperature diminution at more than 20 times that earlier rate at about 0.14 °C per millennium.
- the Holocene interglacial is already 10 – 11,000 years old and judging from the length of previous interglacials the Holocene epoch should be drawing to its close: in this century, the next century or this millennium.
- the beneficial warming at the end of the 20th century to the Modern high point has been responsible the “Great Man-made Global Warming Scare”.
- eventually this late 20th century temperature blip will come to be seen as just noise in the system in the longer term progress of comparatively rapid cooling over the last 3000+ years.
- other published Greenland Ice Core records as well as GISP2, (NGRIP1, GRIP) corroborate this finding. They also exhibit the same pattern of a prolonged relatively stable early Holocene period followed by a subsequent much more rapid decline in the more recent past.
When considering the scale of temperature changes that alarmists anticipate because of Man-made Global Warming and their view of the disastrous effects of additional Man-made Carbon Dioxide emissions in this century, it is useful to look at climate change from a longer term, century by century and even on a millennial perspective.
The much vaunted and much feared “fatal” tipping point of +2°C would only bring Global temperatures close to the level of the very congenial climate of “the Roman warm period”.
Ed’s full post is here.