Showing posts with label habitability. Show all posts
Showing posts with label habitability. Show all posts

Monday, September 18, 2023

A climate of Insanity

by Andrew Glikson

As the emission of greenhouse gases continues, new fossil fuel projects are subsidized, global warming accelerates, bushfires and floods engulf the planet, climate science is ignored, climate change projections are kept away from the public eye, nations invest in killer submarines rather than water spraying aircraft and other fire-fighting equipment, politicians talk about clean coal, radioactive waters are spilled into the ocean, nuclear weapons are readied for a MAD scenario, the media reports sugar-coated semi or untruths, politicians routinely betray their original pledges and playboy billionaires fire rockets at space with plans to settle on Mars.

Inherent in the nature of insanity is the fact that those inflicted by it are unaware of their mental state, nor are crowds of people or for that matter political parties, and business elites, leading populations to catastrophe, from the scale of Jonestown all the way to Auschwitz and Berlin to Vietnam, Iraq and Afghanistan.

Which has now reached a planet-wide scale. According to NASA former chief climate scientist James Hansen, the global temperature in the current El Niño is exceeding the previous El-Niño (2015-16) temperature rise rate of 0.18°C per decade, reflecting the current increase of the Earth Energy Imbalance (EEI) and accelerated heating. The change is in part due to reductions of the cooling effect of human-emitted aerosols (Figure 1). 

Figure 1. Global temperature (relative to 1880-1920 mean for each month) during the El Niño origin year for the 1997-98, 2015-16 and 2023-24 El Niños. The impact of El Niño on global temperature usually peaks early in the year following the year when the El Niño originated. Hansen et al., 2023.

Despite consequent acidification of the oceans, atmospheric geoengineering using sulphur aerosols, reflecting solar radiation, is touted as a last defence from extreme temperature rise. To date, no effective method has been applied to a drawdown of greenhouse gases on a scale required to compensate for the emissions and rise in atmospheric CO₂ (Figure 2). 
Figure 2. Source: https://ourworldindata.org/fossil-fuels#global-fossil-fuel-consumption

Energy-related greenhouse gas emissions have started to grow again, following minor Covid lockdown-related reductions in 2020 (Figure 3).
Figure 3. Global energy-related greenhouse gas emissions 2000-2022, adapted from EIA.

A rise to a mean global temperature to 3°C and 4°C this century is projected by the IPCCPossibly even before such temperatures are reached, the flow of cold ice melt water from Greenland and Antarctica could lead to transient regional to global temperature reversals (Hansen et al., 1998; Bronselaer et al. 2018). These authors state: “Meltwater from the Antarctic Ice Sheet is projected to cause up to one metre of sea-level rise by 2100 under the highest greenhouse gas concentration trajectory (RCP8.5) considered by the Intergovernmental Panel on Climate Change (IPCC). However, the effects of meltwater from the ice sheets and ice shelves of Antarctica are not included in the widely used CMIP5 climate models, which introduces bias into IPCC climate projections.” (Figure 4)

Figure 4. (a) Model surface air temperature (°C) change in 2055–2060 relative to 1880–1920 for modified
             forcings representint the rise of temperatures in the tropics and decline in subpolar latitudes.
           (b) Surface air temperature (°C) relative to 1880-1920 for several ice melt scenarios, representing stadial
        (cooling) episodes related to the effects of ice melt (Hansen et al., 2016) and associated changes.

According to Hansen et al. (2012) “Burning all fossil fuels would create a different planet than the one that humanity knows. The paleoclimate record and ongoing climate change make it clear that the climate system would be pushed beyond tipping points, setting in motion irreversible changes, including ice sheet disintegration with a continually adjusting shoreline, extermination of a substantial fraction of species on the planet, and increasingly devastating regional climate extremes”.

The habitability of Earth and the future of life are issues that are to a large extent avoided by the largely privately-owned corporate media and even by state media, occupied as they are by advertisements, sports contests, fashion parades, cooking shows and popular frenzies such as recently generated by the kissing of a football cup winner.

Is there a way out for humanity and much of nature?

If the multiple $trillions spent by Sapiens on the military and war were directed to environmental defence, including drawdown of atmospheric greenhouse gases, the possibility exists?


A/Prof. Andrew Y Glikson
Earth and Paleo-climate scientist

Andrew Glikson
Books:
The Asteroid Impact Connection of Planetary Evolution
https://www.springer.com/gp/book/9789400763272
The Archaean: Geological and Geochemical Windows into the Early Earth
https://www.springer.com/gp/book/9783319079073
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
The Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
Evolution of the Atmosphere, Fire and the Anthropocene Climate Event Horizon
https://www.springer.com/gp/book/9789400773318
From Stars to Brains: Milestones in the Planetary Evolution of Life and Intelligence
https://www.springer.com/us/book/9783030106027
Asteroids Impacts, Crustal Evolution and Related Mineral Systems with Special Reference to Australia
https://www.springer.com/us/book/9783319745442
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679
The Trials of Gaia. Milestones in the evolution of Earth with reference to the Antropocene
https://www.amazon.com.au/Trials-Gaia-Milestones-Evolution-Anthropocene/dp/3031237080


Tuesday, October 9, 2012

Terraforming Earth

Terraforming

Terraforming is a fascinating idea. Creating Earth-like conditions on other planets or on the moon, or inside structures built in space, that has long been a popular theme in many science fiction stories. 

What are habitable conditions? Many will point at the presence of water and certain minerals. Many will also point at some things our own Earth has, such as an atmosphere that spreads the heat from sunlight around the world, and that has levels of greenhouse gases that keep temperatures within a range that supports life on our planet.

Habitability at risk

At present, changes are taking place in the world that indicate the opposite is happening here on Earth. The conditions that make Earth habitable are at risk in many ways. One threat is the rise in the levels of greenhouse gases in the atmosphere. 

A safe operating space for humanity is a landmark 2009 study that identifies nine essential areas where sustainability is stressed to the limits, in three cases beyond its limits. In the image below, these areas are pictured as wedges. The inner green shading represents the proposed safe operating space for nine planetary systems. The red wedges represent an estimate of the current position for each variable. The boundaries in three systems (rate of biodiversity loss, climate change and human interference with the nitrogen cycle), have already been exceeded.

 From: A safe operating space for humanity, Rockström et al, 2009.

How to reduce the risk

Global warming is caused by emissions such as from burning fuel. Such emissions are still rising. Such emissions must obviously be reduced dramatically, while additional measures are needed to avoid runaway global warming and to bring the atmosphere and oceans back their pre-industrial state as soon as possible.

The table below shows these nine areas in the column on the left, while examples of technologies that could be helpful in the respective area feature in the column on the right. 

1. Climate changeCDR: biochar, carbon air capture, enhanced weathering, algae bags, EVs, renewable energy, clean cooking & heating, LEDs, etc.
SRM: surface and cloud brightening, release of aerosols
AMM & AWIM: methane capture, release of oxygen and diatoms, wetland management, river diversion, enhanced methane decomposition
2. Ocean acidificationenhanced weathering
3. Stratospheric ozone depletionoxygen release
4. Nitrogen & Phosphorus cyclesalgae bags, biochar, enhanced weathering
5. Global freshwater usedesalination, biochar, enhanced weathering
6. Change in land usedesalination, biochar, enhanced weathering
7. Biodiversity lossdesalination, biochar, enhanced weathering
8. Atmospheric aerosol loadingbiochar, EVs, renewable energy, clean cooking & heating, LEDs, etc. 
9. Chemical pollutionrecycling, waste management (separation)

A Comprehensive Plan of Action

At present, governments support polluting products in all kinds of ways, while they use international agreements or the lack thereof as excuses to avoid making the necessary changes.

To facilitate the shift from polluting technologies to clean technologies, political change is imperative and governments around the world should commit to a comprehensive plan of action such as articulated here.

Reducing emissions is obviously an important part of such a plan. This can be effectively achieved by imposing fees on the sales of polluting products, while using the revenues to fund rebates on locally sold clean alternatives. Each nation can start implementing such policies without the need to wait for other nations to take similar action. Clean products are in many respects already economically competitive. Active support by government is the long-awaited signal for local industries to make the necessary investments and create many local clean jobs in the process, while this also supports people's health and has many further benefits.

Moreover, there is a risk of runaway global warming. This risk is unacceptably high and needs to be dramatically reduced as soon as possible, which makes that geo-engineering will have to be an indispensable part of the necessary plan of action. International agreement must be reached on this, not only to minimize possible negative side-effects, but also to ensure that such geo-engineering will not be used as a way for a nation to avoid taking the necessary action to reduce emissions domestically.

Terra is Latin for Earth and sounds sufficiently ancient to indicate that it refers to Earth like it used to be when it was a habitable planet. Indeed, we need a massive effort to restore Terra to the way it used to be. We need to terraform Earth itself.