Royal Society

Green Army: Research and Development

Most analysts would agree that the … chances of keeping below 2°C [are] extremely slim, with 3°C much more likely, and [4°C a real possibility.]

— Four degrees and beyond, Philosophical Transactions of the Royal Society A, 13 January 2011, p 15.

Impacts

CSIRO: Climate Science and Solutions

Impacts

• The impacts of climate change are already clearly visible in Australia. …
• Southern and eastern Australia’s water supply reliability is expected to decline [and] to be accompanied by a growth in water demand due to population growth.
• Development and population growth in Australia’s coastal regions will exacerbate the risks from sealevel rise and … coastal flooding.
• Significant losses of unique Australian animal and plant species are expected to occur … disrupting ecosystem function and causing the loss of ecosystem services.
• The risks to infrastructure include the failure of urban drainage and sewerage systems, more blackouts, transport disruption, and greater building damage. …
• Heatwaves, storms and floods are likely to have a direct impact on the health of Australians, such as causing an increase in heat-related deaths.
  Biological processes such as infectious diseases [such as dengue fever] and physical processes such as air pollution may affect health indirectly …
• Moderate warming [and higher levels of carbon dioxide] in the absence of rainfall declines can be beneficial to some agricultural crops …
  However, these positive effects can be [more than] offset by changes in
  • temperature,
  • rainfall,
  • pests, and
  • the availability of nutrients
• Production from cropping and livestock is projected to decline over much of southern Australia, as is the quality of … crops.

(p 44, emphasis added)

Conversations

ABC Local Radio

Oliver Sacks (1933 – 2015):
[Hans Asperger (1906 – 80) wrote of a sort of “autistic intelligence” that was] scarcely touched by tradition and culture — unconventional, unorthodox, strangely “pure” and original, akin to the intelligence of true creativity.
(An Anthropologist on Mars, 1995, Vintage, 1996, p 253)

Mark Karpelès (1985):
I've spent 30 years living with myself, so I've developed a number of methods and … habits to pass myself off as human.
(The Bitcoin Bandit, 2018)

Ursula Le Guin (1929 – 2018)):
[There comes a point] when you have to choose whether:

• to be like everybody else [for] the rest of your life, or
• to make a virtue of your peculiarities.

(The Dispossessed, Harper, 1974, p 249)

Science

Commonwealth Science and Industrial Research Organisation

Observations

There is a great deal of evidence that the Earth’s climate has warmed over the last century.

• Warming is apparent in a range of climate indicators including increasing temperatures over land and in the oceans, and increases in sea level.
• Global average temperatures have risen in line with climate model projections for the last 20 years, while global average sea levels are rising near the upper end of the climate model projections.
• [The] observed changes to the climate system are consistent with changes expected due to increasing greenhouse gases.

It is very likely that most of the warming over the last 60 years is due to increases in greenhouse gas emissions due to human activity.
(p 1)

Greenhouse Gases

• Greenhouse gases (GHGs) influence the Earth’s climate because they interact with flows of heat energy in the atmosphere.
  The main GHGs influenced directly by human activities are carbon dioxide (CO2), methane, nitrous oxide, ozone, and synthetic gases. …
• The amount of warming produced by a given rise in GHG concentrations depends on ‘feedback’ processes in the climate system …
  The net effect of all climate feedbacks is to amplify the warming …
• The atmospheric level of CO2 (the most important GHG influenced by human activities) rose from about 280 ppm in 1800 to 386 ppm in 2009, and is currently increasing at nearly 2 ppm per year.
• CO2 levels are rising mainly because of the burning of fossil fuels and deforestation.
  Over half of this CO2 input to the atmosphere is offset by natural CO2 ‘sinks’ in the land and oceans …
• To have a 50:50 chance of keeping human-induced average global warming below 2ºC, it will be necessary to stop almost all CO2 emissions before cumulative emissions reach one trillion tonnes of carbon.
  The world has already emitted more than half of this quota since the industrial revolution, and (at current growth rates for CO2 emissions) the rest will be emitted by the middle of this century.
• Climate change is a risk management issue — the longer we take to act and the weaker our actions, the greater the risk of dangerous outcomes.

(p 15)

Projections

• The best estimate of annual average warming by 2030 (above 1990 temperatures) is around 1.0ºC across Australia …
• Drying is likely in southern areas of Australia, especially in winter, and in southern and eastern areas in spring, due to a contraction in the rainfall belt towards the higher latitudes of the southern hemisphere. …
• Intense rainfall events in most locations will become more extreme, driven by a warmer, wetter atmosphere.
  The combination of drying and increased evaporation means soil moisture is likely to decline over much of southern Australia.
  An increase in fire-weather risk is likely with warmer and drier conditions.

(p 35)

Attribution of observed climate changes

[Attribution] studies compare changes in observed climate with various simulations or experiments using coupled atmosphere–ocean general circulation models, also known as Coupled Global Climate Models or Earth System Models …

The combination of observations and climate models are currently the best tools available to differentiate the natural and human-induced effects on the climate system because experimentation with real climate systems is not practically possible.
Experiments using climate models typically include:

• increasing greenhouse gases,
• changing solar radiation,
• changing atmospheric aerosols due to volcanoes and industrial pollution, and
• changing stratospheric ozone.

These models, harnessing the strength of modern computing power, have been shown to be skilful enough in their representation of the real climate system to provide meaningful insights into the causes of recent climate change. …

It is extremely unlikely that the observed global-scale warming is due to natural variability.
Simulations of the last 100 years of climate that include both human and natural influences on climate successfully reproduce observed patterns of global temperature change, whereas simulations that do not include human factors fail to reproduce the observed patterns. …

Consistency [of] warming over [both] land and [ocean indicates] that temperature changes are real rather than an artefact of recording practices.
This is because land and sea temperatures are recorded very differently and are influenced by quite different factors, yet they reveal the same patterns of warming. …

[Because natural annual regional variability] is larger than … over the globe as a whole [it is] difficult to separate the effect of longer term changes from natural variability [at regional scales].
Drought conditions persisted in the south-east from around 1996 to 2010 …
Research has shown that some aspects of this drought are consistent with global warming, but it has not been possible to unequivocally attribute this dry period to the enhanced greenhouse effect.
(p 6)

The drought in the south-west of WA … has been linked with shifts in prevailing weather patterns (e.g. storms and cold fronts) and a general reduction in rainfall associated with those systems.
Some of these changes have been shown to be consistent with human influences (greenhouse gas increases and decreases in stratospheric ozone) in combination with natural climate variability. …

[Increased] atmospheric pressure in … the subtropical ridge (a zone of high pressure or descending dry air across the southern half of the continent, associated with clear skies and low rainfall), has also been shown to be associated with the decline in rainfall across southern Australia, as well as being consistent with human-induced climate change.

There is no unequivocal evidence that long-term changes in the Indian and Pacific oceans, such as changes to the El Niño-Southern Oscillation, have had a major influence on rainfall trends over Australia …
(p 7)