GEO-ENGINEERING. An Overview of Geo-engineering and Bio-geo-engineering (2014)

(Access PDF of this document and references)

Extreme changes in climate are not new to planet Earth. The last Ice Age occurred from around 110,000 to 12,000 years ago and a geological period of warmer global average temperature followed which persists today.

What is new is the size of the human population and the speed at which climate changes are currently occurring. A temperature analysis by NASA scientists shows that Earth’s average global temperature has increased by about 0.8°Celsius since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade.

Scientists suggest that a rise of up to 1.50C is safe, while 20C has the potential to severely disrupt and damage ecological stability worldwide with concomitant economic consequences and the risk of endangering millions of lives. A rise of 30C will be catastrophic.

Even this early in the twenty-first century news headlines regularly tell of climate related catastrophes. In 2003, a ‘heat wave’ led to the deaths of some 30,000 people across Europe. The high temperatures melted glaciers in the Switzerland Alps, causing avalanches and flash floods. Arctic sea ice melt has resulted from a rise in temperature and has altered atmospheric circulation in a way that led to extreme snow and ice in the Northern Hemisphere. The 2013–14 North American ‘cold wave’ extended from December 2013 to April 2014 with impacts as far south as Mexico: heavy snow and ice; aircraft grounded; electricity supply failures.

Environmentally induced population movements or displacement is and will be one of the consequences of extreme weather conditions and rising sea levels. Migration may be the only viable strategy for many communities. ‘Environmental refugees’ describes people who have been forced to leave their traditional habitat, temporarily or permanently, because of a marked environmental disruption, be it natural and/or triggered by people, that threatens their existence and/or seriously affects their quality of life.

During 2012, approximately 32.4 million people were displaced by environmental disasters; 98% caused by climate- and weather-related events, especially flooding. Half of Bangladesh’s population live less than five metres above sea level. Scientists predict the country will lose 17 percent of its land by 2050 due to encroachment by rising sea levels, and create up to 20 million environmental refugees. Kiribati and other low-lying islands of the Pacific also battle rising sea levels.

Worldwide, desertification currently affects between 100 and 200 million people.5 In China, the Gobi desert is expanding over 10,000 square kilometres annually and can now be seen from the capital, Beijing. Droughts in sub-Saharan Africa and other parts of that continent have lead to the deaths of domestic and wild animals and crops, resulting in famine. Droughts have also hit countries traditionally well provided for by weather systems. In 2013, most of New Zealand suffered drought.

If Earth experienced a two-degree rise in temperatures by the end of this century, which many predict could happen, at a minimum we would see more of the foregoing: water stress, for crops and drinking, increasingly worse floods, snowfalls and heat waves, coastal erosion, and the potential elimination of up to 30 percent of animal and plant species.

The international community has agreed to limit temperature rise to 20C above pre-industrial levels. Achieving this limit would not prevent, but may limit some adverse effects. The Intergovernmental Panel on Climate Change (IPCC) concludes that avoiding a two degrees rise means reducing emissions by at least two fifths by 2050, and dramatically increasing the energy generated from low-carbon energy sources by the same date. In April 2014, it released the last of three reports which assessed the physical evidence of climate change, the expected impacts over the course of the 21st century, and what is needed to curb the rise in levels of greenhouse gases. It says to combat climate change may mean using new, untested technologies to reduce the level of CO2 in the atmosphere. The magnitude and gravity of the problems demand immediate attention. Science is asking how can Earth’s climate be manipulated on a global scale to lower temperatures?

This is where geo-engineering and bio-geo-engineering propose remedial actions. As with all new technologies, science has to evaluate the ideas and their practical implementation which revolves around technical feasibility and cost, and more importantly around issues of ethics: governance, justice, morality and the very role humanity should, could and will play on Earth.

These emerging technologies must run parallel to and complement emission controls and communities living more sustainably, not as a replacement for these. So far, most research on geo-engineering and bio-geo-engineering has consisted of computer modelling or laboratory testing only with few actual applications. The focus is on two general areas:

• Reducing the levels of carbon dioxide (CO2) from Earth’s atmosphere to address a root cause of global warming. CO2 is one of the main offending greenhouse gases (GHGs).

• Managing solar radiation with the aim of offsetting the effects of GHGs by causing Earth to absorb less solar radiation and thereby become cooler.

Key proposals for CO2 removal include:

• Terrestrial based techniques such as land use and afforestation, use of biomass with CO2 sequestration, enhanced weathering on land and chemical air capture/carbon sequestration, as well as marine techniques such as ocean fertilization, alkalinity enhancement, and overturning circulation.

• Solar radiation management (SRM) techniques which revolve around changing cloud or surface albedo – through roof whitening, or through various grassland, crop or desert surface albedo changes. Other proposed SRM techniques are space-based. They may involve injection of aerosols into the stratosphere, or using mirrors and the like in Earth’s orbit or between the sun and Earth.

NB In this overview, the term geo-engineering will be used for all applications except where the proposal involves organisms content where bio-geo-engineering will be used, bio’ meaning life.

Geo-engineering describes a process of deliberate and large-scale intervention in Earth’s climate system

Can proposed geo-engineering techniques work?

The US Government Accounting Office, in a September 2011 study on the technical status - maturity, potential effectiveness, cost factors, and potential consequences - of proposed geo-engineering technologies concluded that none of the proposed techniques were ready to address global climate change. (See Table 1 on page 7 and Table 2 on page 8 for an adapted summary of their findings.)

None of the carbon dioxide removal (CDR) based geo-engineering proposals are ready for use and do not seem to offer acceptable effectiveness. Most come with serious environmental downsides.

While expensive and currently largely at the idea stage, SRM techniques do offer the possibility of working, albeit with potentially serious or even disastrous environmental, economic and human health side effects. Furthermore, once deployed these technologies must be maintained to continue their effect on Earth’s temperatures. Abrupt cessation may result in unpredictable temperature rises.

The Solar Radiation Management Governance Initiative (SRMGI) - formed by the UK Royal Society, the Environmental Defence Fund (EDF) and The World Academy of Sciences (TWAS) - concurs that limited computer modelling so far indicates global temperatures could be reduced within a few months of deployment, but with potentially serious regional consequences, climatically and socio-politically. They also make it clear SRM is not a substitute for atmospheric GHG reduction.

Currently, it is unclear if and how the safety of any of these technologies can realistically be assessed. Probably the safest laboratory technique, climate modelling, has numerous limitations, including lack of accuracy and precision and lack of computer power.

Conventional risk assessment - with its premise that risk events can be averaged out over time and space and that the probabilities can be estimated to determine the likelihood of an event occurring - is unlikely to be applicable in the case of geo-engineering. Similarly, the definition of risk itself, conventionally defined as hazard multiplied by exposure, appears to have little application in the case of geo-engineering technology.

Implicit in this paradigm of risk assessment is the assumption that uncertainties can be known or estimated. Geo-engineering proponents are proposing to use untested techniques on what are complex systems. Unpredictability is especially pronounced in complex systems and geo-engineering techniques are designed to interfere with these complex systems to change their behaviour. Precisely because it is hard to understand complex systems in their many interacting levels, using geo-engineering techniques may cause novel and unprecedented effects that are virtually impossible to mitigate. We may not be able to predict how the system will behave, until we have interfered with it.

The following are examples of proposed or actual geo-engineering applications:

‘Cool’ surfaces

Over 95% of cars and small trucks in California are equipped with air conditioners. A ‘cool’ cars project there has aimed at reducing air conditioning usage of cars by lowering in-car air temperatures.

Dark cars reflect only 10% of sunlight while ‘cool’ light-coloured cars can reflect 60%. Light-colours reduce the amount of heat transmitted into the interior of a car, decrease the need for air conditioning, save on fuel consumption, and decrease the emission of GHGs and urban air pollutants.

‘Cool’ roofs and other ‘cool’ surfaces give similar results. A dark roof reflects 20% of sunlight, a ‘cool’ roof 80%. A dark pavement reflects 10%, a ‘cool’ pavement 40%. However, on a global scale these techniques are insignificant. (See Table 2 on page 8.)

Ocean iron fertilization

Ocean iron fertilization is the intentional introduction of micro- or nano-iron particles in the upper ocean layer to stimulate a phytoplankton bloom. Iron is a necessary trace element for photosynthesis and such fertilization occurs naturally when:

• nutrient-rich deep-water wells up to the surface;
• wind-blown dust travels far over the ocean; and
• iron-rich minerals are deposited in the ocean by glaciers, rivers and icebergs.

Relatively small amounts of iron can trigger large phytoplankton blooms. Plankton generate calcium or silica carbonate skeletons which sink when they die. Most of the sinking skeletons dissolve, are re-mineralized well above the seafloor and eventually re-released into the atmosphere. The CO2 in the skeletons reaching the ocean floor is sequestered for eons.

Proponents of geo-engineering propose artificially inducing phytoplankton bloom.

For ocean studies that have examined the fertilization effects of iron particulates see http://en.wikipedia.org/wiki/Iron_fertilization.

View the ocean division zones and depths on http://en.wikipedia.org/wiki/Ocean.

Stratospheric sulphate aerosols

Proponents claim that releasing sulphate in the stratosphere will increase global ‘dimming’, that the presence of the particulates will reduce the amount of direct irradiance at Earth’s surface. Global dimming can occur by natural means and have a cooling effect. It may be due to particulates in the atmosphere created by human activity or to particulates ejected by erupting volcanoes. In June 1991, the eruption of Mount Pinatubo discharged sulphur dioxide (SO2) into the stratosphere which immediately began converting into sulphuric acid (H2SO4) aerosols.

The H2SO4 aerosol-cloud spread around the planet in three weeks and caused a decrease in the net radiation reaching Earth's surface. The lower stratosphere also warmed immediately following the eruption and subsequently cooled to the lowest temperatures recorded causing changes in atmospheric circulation. Other effects included surface cooling in 1992 and 1993. The Pinatubo ‘climate forcing’ was stronger than the opposite, warming affects of either the El Niño event or anthropogenic GHGs in the period 1991 to 1993.

Proponents of stratospheric aerosols propose seeding the atmosphere with precursor sulphide gases: for example, dimethyl sulphide (CH3SCH3), carbonyl sulphide (COS), sulphuric acid (H2SO4), hydrogen sulphide (H2S) or sulphur dioxide (SO2). These precursor gases would gradually oxidize, through both gaseous and aqueous reactions, to end products involving the sulphate anion (SO42-) in combination with various other cations.

The potential effects may well be tragic and may include disruption of Asian and African summer monsoons with accompanying reduction in precipitation (rainfall), as well as delayed ozone layer recovery in the southern hemisphere and about a 30-year delay in recovery of the Antarctic ozone hole.

To read more and access references, download this publication:

Download

Information