Mike Bell has also been published in the New Scientist
Recent archaeological research has shown that over the last three quarters of a million years, several species of Homo lived in Britain at various times. The gravitational interactions between Earth, Jupiter and Saturn and the milankovitch cycles led to repeated ice ages that made Britain uninhabitable for the Homo species. The end of the last ice age, the beginning of the Holocene era (the period since the last ice age till the present day), provided conditions suitable for the only surviving species of Homo (humans/Homo sapiens) to re-enter Britain on a permanent basis.
The global rise in sea level flooded the southern North Sea and cut the English Channel which made it difficult for our Neolithic ancestors to leave Britain. Prior to Britain becoming an island our hunter gatherer forebearers would have followed the migratory herds that ranged across Europe with only a seasonal occupation of Britain. It is possible that the western coasts of Britain supported a permanent population of fisher folk before the Holocene began, but, there is no archaeological evidence to this conjecture.
Global temperature for the first 5,000 years of the Holocene era remained stable. We know this from proxy measurements such as the thickness of the tree rings which reflect the growing conditions the tree experienced. Archaeologists now have an almost complete record of seasonal growth throughout the duration of the Holocene. However, 5,000 years ago global temperatures started to decline, and reached a low point during the little ice age, a time when frost fairs were held in London on a frozen river Thames.
It is difficult to define when the anthropocene began (the period where human activity has been the dominant influence on the environment and climate). Despite this the decline in global temperature did coincide with the beginning of agriculture, but it is noticeable that the temperature decline took five times as long as the temperature rise – the rise that lead up to the Holocene. It may be that the Earth takes longer to cool than it takes to warm up.
There is no doubt that human activity injected and still injects more and more greenhouse gases into the atmosphere due to agriculture, which is what made civilisation possible. However, as civilisation required more agricultural space the clearance of forests caused the natural carbon cycle to alter which lead to higher levels of atmospheric CO2: A burnt or rotting tree emits CO2; it does not absorb and sequester it like a living tree and the soil around the living tree would. The advent of rice production on flooded paddy fields in south East Asia would also have produced large quantities of methane, an even more potent greenhouse gas, as anaerobic bacteria released the carbon stored in the soil. Since Milankovitch cycles are relentless, agriculture only delayed the onset of another ice age. Furthermore, it took the industrial revolution with its enormous release of fossil carbon to reverse the decline in global temperature. That’s the history; it is now time to reflect on the present.
Presently, global temperature is now as high, maybe slightly higher, than during the warmest periods of the Holocene. Average global temperature has risen 0.8 C above pre-industrial levels, and average arctic temperature has risen 2.0 C within the same period. These warm periods of the Holocene were due to increased sunlight warming the Northern Hemisphere. Although, you can’t say things are what they used to be.
Atmospheric CO2 levels were much lower back then than today the oceans were less acidic: Shellfish and corals were more able to grow their calcium carbonate armour, fish stocks were not depleted, huge numbers of deep diving cetaceans added nutrients to oceanic surface waters and the dead oceanic zones of today were once thriving ecosystems that must have sequestered carbon, as their bones and shells fell through the water and became part of the ooze on the oceanic floor. Climatologists have ascertained that the jet stream is powered by the temperature difference between the equator and the arctic. The jet stream is no longer the powerful force it once was when it confined arctic air to the Arctic Circle. The weakened jet stream now meanders all over the northern hemisphere, bringing arctic frosts to the orange groves of Florida and winter droughts and floods to north Western Europe. In Britain, weather forecasters refer to these meanders as “blocking events”. These blocking events are unpredictable: a butterfly may flap its wing in Wisconsin and change the course of a blocking event that may occur thousands of miles away and weeks later. It is not possible to have enough sensors connected to sufficient processing power to predict the events of a butterfly’s wing flap on a turbulent, dynamically flexible mixture of dust, atoms and molecules when uncertainty is the hallmark of quantum interactions as Spock may have said, but didn’t “it’s chaos Jim, just as we know it!”
What is certain is that as the Arctic warms relative to the Tropics, blocking events will become more frequent and the associated weather will become more extreme. Britain looks set for many more cool wet summers and cold dry windy winters with an increasing flood risk.
One suggestion is to spray Sulphate from high flying planes so that Sulphate aerosols could reflect sunlight back into space and thus cool the planet. It would work it seems, until you consider what would happen. The Sulphate aerosols would become condensation nuclei and would then fall as Sulphuric acid rain. No thanks! Enriching the surface water of the oceans with Iron has been tried and plankton blooms did follow, on some of the times. The problem is that the costs were high, and the only certain results are the profits the enrichment company makes from the carbon credits it claims. It is easier and cheaper to just stop hunting whales.
One idea, which was presumably dreamt up by a manufacturer of ping-pong balls, was to release billions of ping-pong balls into the Arctic Ocean in order to increase its Albedo. I agree Geo engineering an increase in the albedo of the Arctic is a good idea. Cooling the Arctic by reflective sunlight back into space would increase the temperature difference between the Arctic and the Tropics stabilise the jet stream and reduce the number and scale of blocking events. Floating ping-pong balls does not seem to me to be an environment friendly way to do it.
Since the dawn of civilization the Aral Sea has benefited the climates of the world. With its 66,000 km₂ it did contribute to moderating temperature, humidifying air and land. The death of the Aral Sea, caused by crop irrigation, altered weather patterns permanently, creating more continental extremes as weather fronts no longer encounter the moderating humidity from the evaporating Aral Sea. This drying up of the Aral Sea is considered by many environmentalists to be the biggest environmental disaster of all time, which may only be eclipsed by the total meltdown of Earth’s Ice Caps. The Soviet Union had a plan, to divert water from other major rivers in the Aral Basin to refill the Aral Sea. Unfortunately, the Soviet Union collapsed before this plan was realised. The region surrounding the former Aral Sea is now a salt scorched desert. Refilling the Aral Sea with what is essentially waste water would turn an enormous desert into an enormous food producing carbon sink. The Romans, who built one of the earliest plumbing systems – aqueducts that transported water for miles to where it was needed, could have done this, and would have done this, so why don’t we? There are vast regions of central Asia that are now desert but could become food producing carbon sinks with a little Roman Hydrological house.
My idea is to anchor polypropelene buoyed ropes stretched between the islands of Nuuanu, the islands of the Sulu Archipelago, and Elsmere Island and Greenland, in order to prevent the dispersal of sea ice in these areas, into the North Atlantic. Sea ice is more reflective than ping pong balls, not using ice breaking ships would also help stabilise Arctic sea ice. By allowing ice shelves attached to land to remain connected to sea ice. If we want to experience long hot summers in Britain again we must increase the Albedo of the Arctic. Well that’s my idea, what’s yours?