Arctic News: drawdown

Showing posts with label drawdown. Show all posts

Tuesday, January 11, 2022

Accelerating global warming and amplifying feedbacks: The imperative of CO₂ drawdown

by Andrew Glikson

Satellite measurements indicate that 2021 was one of the warmest years on record, with the past seven years being the hottest period recorded globally (Met Office, January 10, 2022). Attempts at global emission reductions, lowered in part due to COVID-19 economic slow-down, appear to have little effect on atmospheric CO₂ rise, as indicated by the current rise of atmospheric carbon dioxide to record high levels of 420 ppm despite reduced emissions in 2020-2021 (Figures 1 and 2).

Figure 1. A. Mean global CO₂ levels from 800,000 years to the present (NASA).
B. Mean global temperature rise from 1850 to 2021 (Berkeley Earth).

As stated by CarbonBrief: “The year so far has been one of extremes, featuring record-shattering heatwaves, wildfires and flooding, as well as the warmest-ever northern-hemisphere summer – June, July and August – in the global land-surface record.”

Whereas climate negotiations mostly focus on possible reductions in emissions, the cumulative buildup of greenhouse gases is determining the future of the terrestrial climate. According to NASA “Once it’s (CO₂) added to the atmosphere, it hangs around, for a long time: between 300 to 1,000 years".

Other estimates are much longer. Because of the longevity of CO₂ and other greenhouses gases in the atmosphere, a decrease in carbon emissions, while essential, is not sufficient to reduce CO₂ levels in the atmosphere in time.

According to the IPCC “about 50% of a CO₂ increase will be removed from the atmosphere within 30 years, and a further 30% will be removed within a few centuries. The remaining 20% may stay in the atmosphere for many thousands of years”. According to the US EPA (Environmental Protection Agency) “Atmospheric lifetime: 50-200 years. No single lifetime can be defined for CO₂ because of the different rates of uptake by different removal processes”.

According to Solomon et al. (2009) and Eby et al. (2009) high levels of CO₂ on the scale of 10² to 10³ ppm would persist for millennia.

Global emission reductions, decreased in part due to COVID-19 economic slow-down, have little effect on the atmospheric CO₂ level, as indicated by the current trend of atmospheric carbon dioxide, at record high levels despite reduced emissions in 2020 (Figure 2). This suggests to a significant extent the current rise in atmospheric CO₂ arises from amplifying feedbacks from land and ocean.

Figure 2. A. Observed and forecast monthly and annual CO2 concentrations at Mauna Loa.
Observations from the Scripps CO2 program, forecasts from Met Office. Credit: Met Office.
B. Measured and forecast monthly CO2 concentrations at Mauna Loa Observatory, Hawaii.
Black line: measurements by the Scripps Institution of Oceanography, UC San Diego. Solid red line
with vertical uncertainty bars: forecast by the Met Office, including the revised forecast for 2020
issued in May 2020 accounting for reduced global emissions due to societal responses to Covid-19.
The forecast uncertainty estimate is ± 0.6 ppm. Dotted red line: original Met Office forecast for
2020 issued in January 2020, not accounting for Covid-related emissions reductions.
Horizontal dashed blue line: 417 ppm, a 50% increase above 278 ppm, the level in 1750-1800
from ice core records.

All taking place notwithstanding hollow promises made at COP26, a meeting noted for the near-absence of contributions by climate scientists.

In trying to avoid an exponential rise in greenhouse gases toward catastrophic levels, one option exists, namely urgent attempts at drawing down at least part of the CO₂ concentration of the atmosphere. The $trillions of dollars required, constituting the “Price of the Earth”, may not exceed the $trillion dollars military expenses spent by the world over the last 70 years, including nuclear missile fleets which constitute a separate threat for life on Earth, as warned by Albert Einstein: “The unleashed power of the atom has changed everything save our modes of thinking and we thus drift toward unparalleled catastrophe”.

Andrew Glikson

A/Prof. Andrew Glikson

Earth and Paleo-climate scientist
School of Biological, Earth and Environmental Sciences
The University of New South Wales,
Kensington NSW 2052 Australia

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
Climate, Fire and Human Evolution: The Deep Time Dimensions of the Anthropocene
https://www.springer.com/gp/book/9783319225111
The Plutocene: Blueprints for a Post-Anthropocene Greenhouse Earth
https://www.springer.com/gp/book/9783319572369
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 Event Horizon: Homo Prometheus and the Climate Catastrophe
https://www.springer.com/gp/book/9783030547332
The Fatal Species: From Warlike Primates to Planetary Mass Extinction
https://www.springer.com/gp/book/9783030754679

Sunday, November 24, 2019

The breach of the Paris Agreement

By Andrew Glikson
Earth and climate scientist
Australian National University

Since its inception the Paris Agreement has been in question due to, among other:

its broad definition, specifically holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels;
its non-binding nature; and
accounting tricks by vested interests.

The goal assumes pre-determined limits can be placed on greenhouse gas levels and temperatures beyond which they would not continue to rise. Unfortunately these targets do not appear to take account of the amplifying positive feedback effects from land and oceans under the high cumulative greenhouse gas levels and their warming effects. Thus unfortunately the current high CO₂ levels of about 408 ppm and near-500ppm CO₂-equivalent (CO₂+methane+nitrous oxide) would likely continue to push temperatures upwards.

Significant climate science evidence appears to have been left out of the equation. The accord hinges on the need to reduce emissions, which is essential, but it does not indicate how further temperature rise can be avoided under the conditions of a high-CO₂ atmosphere, which triggers carbon release, unless massive efforts at sequestration (drawdown) of greenhouse gases are undertaken. Inherent in global warming are amplifying positive feedbacks, including albedo (reflection) decline due to the melting of ice and the opening of dark water surfaces, increased water vapor contents of the atmosphere in tropical regions which enhances the greenhouse effect, reduced sequestration of CO₂ by the warming oceans, desiccation of vegetation, fires, release of methane from permafrost and other processes. This means that even abrupt reductions in emissions may not be sufficient to stem global warming, unless accompanied by sequestration of greenhouse gases from the atmosphere to a lower level, recommended as below 350 ppm CO₂ by James Hansen, the leading climate scientist.

The world is on track to produce 50% more fossil fuels than can be burned before reaching the limit prescribed by the Paris Agreement, with currently planned coal, oil and gas outputs making the Paris Agreement goal impossible. Projected fossil fuel production in 2030 being more than is consistent with 2°C, and 120% more than that for 1.5°C.

Unbelievably, according to the International Monetary Fund, “In 2017 the world subsidized fossil fuels by $5.2 trillion, equal to roughly 6.5% of global GDP”, which is more than the total the world spends on human health. Such subsidies cannot possibly be consistent with the Paris Agreement. The pledge to end fossil fuel subsidies by 2025 by the G7 nations, with exceptions by the UK and Japan, may come too late as global CO₂ concentrations, already intersecting the stability limits of the Greenland and Antarctic ice sheets, are rising at a rate of 2 to 3 ppm per year, the highest in many millions of years.

Despite the scientific consensus regarding the anthropogenic origin of global warming, the world’s biggest fossil fuel corporations are taking a defiant stance against warnings that reserves of coal, oil and gas are already several times larger than can be burned if the world’s governments are to meet their pledge to tackle climate change. ExxonMobil said new reserves in the Arctic and Canadian tar sands must be exploited. Peabody Energy, the world’s largest private coal company, said global warming was “an environmental crisis predicted by flawed computer models”. Glencore Xstrata said that governments would fail to implement measures to cut carbon emissions. The World Bank and Bank of England have already warned of the “serious risk” climate action poses to trillions of dollars of fossil fuel assets.

Not to mention the risks to the living Earth and its billions of inhabitants!

The apparent neglect of scientific advice is not an isolated instance. It is not uncommon that climate reports are dominated by the views of economists, lawyers, bureaucrats and politicians, often overlooking the evidence presented by some of the world’s highest climate science authorities. Whereas the IPCC reports include excellent and comprehensive summaries of the peer-reviewed literature, the summaries for policy makers only partly represent the evidence and views of scientific authorities in the field, including those who have identified global warming in the first place.

Figure 2. from: James Hansen, data through June 2019

There exists a tendency in the media to report averages, such as average global temperature values, rather than the increasingly-common high zonal, regional and local anomalies.

For example, the annual mean global temperature rise of for 2018 is about one third the Arctic mean temperature rise (Fig. 2). Given that developments in the Arctic bear major consequences for climate change, the global mean does not represent the seriousness of the climate crisis.

Another example is the way extremes weather events are reported as isolated instances, neglecting the rising frequency and intensity of hurricanes, storms, fires and droughts, indicated in frequency plots (Fig 3.).

Figure 3. Rise in geophysical, meteorological, hydrologocal and climatological events. Munich RE.

It is not until international and national institutions take full account of what climate science is indicating that a true picture of the climate crisis will be communicated to the public.

Andrew Glikson