Submission by the Arctic Methane Emergency Group (AMEG) to the Environment Audit Committee’s Inquiry on Arctic Sustainability - Changes in Arctic and Impacts
Changes in the Arctic and their impact
We are glad that the committee recognise that a new look is required at the policy framework, in the light of recent scientific evidence, because there is much new evidence to support our assertion that the Arctic is in a process of dangerous and potentially irreversible meltdown – a switch to a low albedo state. The Arctic continues to warm much faster than the global average of 0.2C per decade. The El Niño caused a surge in global warming but an even greater surge in Arctic warming. Huge changes are in progress, as warm water from the Atlantic is flowing further and further into the Arctic Ocean, reaching as far as Novaya Zemlya. Svalbard has been free of sea ice this winter, which is unprecedented. Storm systems have reached to central Arctic, breaking up the sea ice and mixing the low salinity water on the surface with higher salinity water below. All this suggests that the Arctic is rapidly heading for a low albedo state. Once the Arctic Ocean has an anticlockwise gyre of surface water, in place of a clockwise gyre of sea ice, the switch to low albedo state will be complete. In the past, air has descended at the poles producing a prevailing north-easterly wind at high latitudes. Now air will rise over the ocean, being warmer than surrounding land masses. Air will probably be sucked in between Greenland and Norway, as we have seen with storm tracks and a meandering jet stream. A new pattern of air circulation could be established for the Northern Hemisphere, affecting climate as far as the tropics or even into the Southern Hemisphere, as the thermal balance between hemispheres is upset. Longer spells of stuck weather can be expected. In particular floods could be even worse for the UK, with a meandering jet stream picking up moisture from tropical oceans and dumping it consistently in the same region, as happened recently. The cost of flood damage, and the cost of building ever greater defences against floods, has escalated in the UK as in the US and elsewhere. The problem for London, with rising flood risk from the extreme rain, storm surge and higher sea level (see below), is humongous.
Meanwhile other processes are at work in the Arctic as it continues warming. The Greenland Ice Sheet (GIS) is melting ever faster. It is showing alarming signs of disintegration with an increase in icequakes and a huge crack in the ice opening up inland from the west coast. Recent evidence suggests that past disintegration of the GIS, at the end of the Eemian, caused mega-tsunamis, as huge blocks of ice slammed into the sea. This is a potential hazard for the UK, especially nuclear power stations in the Bristol Channel where tsunami waves would be amplified. There is strong evidence that a tsunami struck the Bristol Channel in 1607, and yet there appear to be no plans in case a tsunami struck again.
The GIS meltwater is increasing to the point of causing a cold anomaly in the North Atlantic. The Atlantic Meridional Overturning Circulation (AMOC) has been thoroughly disrupted, both as a result of a combination of increased meltwater and a loss of the subduction vortexes in the Greenland Sea as sea ice has retreated. A profound weakening of AMOC has huge implications for warming of the Southern Ocean and discharge of Antarctic glaciers, some of which are beyond their tipping point. Thus one way or other, the continued warming of the Arctic is liable to produce massive sea level rise – perhaps as much as the half metre per decade (as recorded for the huge meltwater pulses which occurred following the last glacial maximum). Such sea level rise would be devastating for low-lying cities such as London. Sir David King has calculated that a rise of 0.3 to 0.4 metres would be devastating for many major cities around the world. On current trends, sea level could rise 0.5 metres by 2040 or 2050.
Then there is the methane to be considered. Emissions from thawing land permafrost are growing remorselessly but we are even more concerned about emissions from subsea permafrost. There are more than two millions square kilometres of subsea permafrost where former frozen land has been inundated as sea levels rose following the last glacial maximum, some 20,000 years ago. Methane emissions from the Arctic Ocean’s continental shelf off Siberia have grown alarmingly since our 2011 report to the EAC, as observed by the Russian scientists, Shakhova and Semiletov. Where formerly they were seeing plumes of bubbles of a few metres diameter, they are now seeing plumes a kilometre across and more. This has happened as the temperature at the seabed has risen by as much as 7C. So it can be assumed that the permafrost beneath the seabed is being thawed from above by warm seawater and from below by geothermal heat. Any methane hydrate caged by permafrost is liable to disassociate, releasing methane gas. The permafrost is become perforated in many places. Any methane gas beneath the permafrost is liable to escape through perforations in the permafrost. Thus the methane may be coming from hydrate in the permafrost or from methane trapped beneath the permafrost or both. In any case, the situation is serious because of the hundreds if not thousands of gigatons of methane stored in permafrost and beneath it. Because methane is such a potent greenhouse gas, a release of a tiny fraction (just one gigaton per annum) from the vast store of methane could double the rate of global warming from 0.2C per decade to 0.4C per decade. Such an outburst is thus a huge risk to humanity.
The Arctic which we love for its beauty and wild life is melting away in front of our eyes. And nothing is being done about it! Does it really matter?
The loss of an entire ecosystem is one thing; the effect on the rest of the planet is another. The Arctic snow and ice acts as a giant mirror to reflect sunshine back into space and keep the Arctic frozen. This has huge benefits for the rest of the planet:
- the Arctic cools water from the Atlantic and circulates it round the whole planet;
- the Arctic keeps the Greenland Ice Sheet frozen, thus preventing 7 metres of sea level rise if it all melted;
- the Arctic keeps an ice and permafrost lid on vast quantities of the natural gas, methane, thus preventing this potent greenhouse gas from causing a catastrophic surge in global warming;
- above all, the Arctic keeps weather systems in place such that climates around the world stay constant.
The Arctic has provided these benefits for thousands of years, but we do not expect it to continue. Changes are already happening as the Arctic warms much faster than the rest of the planet. For example, floods, droughts and other weather extremes are becoming more common. The whole situation will get worse as time goes on.
However the rot can be stopped if we act now. We must refreeze the Arctic, starting with the sea ice. Here are some techniques which could be used:
- water flowing into the Arctic can be cooled using a marine cloud brightening technique: spray devices produce a mist of fine seawater droplets; these evaporate producing microscopic particles which are wafted into clouds by natural air circulation; the particles act as cloud condensation nuclei which have the effect of brightening the top of the cloud and cooling the water beneath; the cooled water flows into the Arctic;
- sea ice can be thickened so it doesn't melt away in summer: the use of “ice shields” has been proposed;
- snow can be created to reflect more sunshine back into space: the seeding of clouds to produce snow has been proposed.
An urgent task is to develop these techniques and prepare for large-scale deployment. Modelling, trialling, evaluation and monitoring will play essential roles in successful deployment of selected technologies.
Other restorative action is needed, because the rest of the planet is also warming and our oceans are dying. Again there are several techniques available. One possibility is to restore life in the oceans, using plant-like algae and nutrients. This will remove CO2 from the air which has been causing the planet to warm.
Conventional wisdom says that climate change is all about reducing our carbon emissions, but this is only half the story! We need restorative action as well to actively remove CO2 from the atmosphere, to actively suppress methane emissions and, even more urgently, to refreeze the Arctic.
Full climate restoration for the safety and wellbeing of future generations will require a significant international response to reduce climate forcing from all major sources. We recommend that the total climate forcing should be halved by 2030: restoring Arctic albedo, removing CO2 from the atmosphere and suppressing methane emissions. At the same time, the fertility of soils and oceans needs to be maintained or increased to feed a growing population. This is a huge challenge but also a huge opportunity for investment. It is suggested that the government might lean on the fossil fuel industry to provide much of the required funding. They also have considerable engineering expertise to offer.
Note that international collaboration with the UK in climate restoration should be considered a force for good, since everyone benefits. As the old norms are restored, crop yields will grow and the conflict arising from famine should subside, e.g. in NE Africa and the Middle East. Thus there will be a peace dividend from climate restoration, which could be a point of pride for the UK, assuming we participate.