Andrew Glikson: Another link between CO2 and mass extinctions of species

by Andrew Glikson, The Conversation, March 22, 2013

It’s long been known that massive increases in emission of CO₂ from volcanoes, associated with the opening of the Atlantic Ocean in the end-Triassic Period, set off a shift in state of the climate which caused global mass extinction of species, eliminating about 34% of genera. The extinction created ecological niches which allowed the rise of dinosaurs during the Triassic, about 250–200 million years ago.

New research released this morning in Science Express has refined the dating of this wave of volcanism. It shows marine and land species disappear from the fossil record within 20,000 to 30,000 years from the time evidence for the eruption of large magma flows appears, approximately 201 million years ago. These volcanic eruptions increased atmospheric CO₂ and increased ocean acidity.

Mass extinctions due to rapidly escalating levels of CO₂ are recorded since as long as 580 million years ago. As our anthropogenic global emissions of CO₂ are rising, at a rate for which no precedence is known from the geological record with the exception of asteroid impacts, another wave of extinctions is unfolding.

Mass extinctions of species in the history of Earth include:

• the ~580 million years-old (Ma) Acraman impact (South Australia) and Acrytarch (ancient palynomorphs) extinction and radiation
• Late Devonian (~374 Ma) volcanism, peak global temperatures and mass extinctions
• the end-Devonian impact cluster associated with mass extinction, which among others destroyed the Kimberley Fitzroy reefs (~360 Ma)
• the upper Permian (~267 Ma) extinction associated with a warming trend
• the Permian-Triassic boundary volcanic and asteroid impact events (~ 251 Ma) and peak warming
• the End-Triassic (201 Ma) opening of the Atlantic Ocean, and massive volcanism
• an End-Jurassic (~145 Ma) impact cluster and opening of the Indian Ocean
• the Cretaceous–Tertiary boundary (K-T) (~65 Ma) impact cluster, Deccan volcanic activity and mass extinction
• the pre-Eocene–Oligocene boundary (~34 Ma) impact cluster and a cooling trend, followed by opening of the Drake Passage between Antarctica and South America, formation of the Antarctic ice sheet and minor extinction at ~34 Ma.

Throughout the Phanerozoic (from 542 million years ago), major mass extinctions of species closely coincided with abrupt rises of atmospheric carbon dioxide and ocean acidity. These increases took place at rates to which many species could not adapt. These events – triggered by asteroid impacts, massive volcanic activity, eruption of methane, ocean anoxia and extreme rates of glaciation (see Figures 1 and 2) – have direct implications for the effects of the current rise of CO₂.


Click on graphs to enlarge.

Figure 1. Trends in atmospheric CO2 and related glacial and interglacial periods since the Cambrian (542 million years ago), showing peaks in CO2 levels (green diamonds) associated with asteroid impacts and/or massive volcanism. CO2 data from Royer (2004 and 2006).

Figure 2. Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including the Paleocene–Eocene Thermal Maximum, early Oligocene, mid-Miocene, late Pliocene, Eemian (glacial termination), Dansgaard–Oeschger cycles, Medieval Warming Period, 1750–2012 and 1975–2012 periods.

In February 2013, CO₂ levels had risen to near 396.80 ppm at Mauna Loa Atmospheric Observatory, compared to 393.54 ppm in February 2012. This rise (3.26 ppm per year) is at the highest rate yet recorded. Further measurements show CO₂ is at near 400 ppm of the atmosphere over the Arctic. At this rate the upper stability threshold of the Antarctic ice sheet, defined at about 500–600 ppm CO₂ would be reached later this century (although hysteresis of the ice sheets may slow down melting).

Our global carbon reserves (including coal, oil, oil shale, tar sands, gas and coal-seam gas) contain considerably more than 10,000 billion tonnes of carbon (see Figure 5). This amount of carbon, if released into the atmosphere, is capable of raising atmospheric CO₂ levels to higher than 1,000 ppm. Such a rise in atmospheric radiative forcing will be similar to that of the Paleocene–Eocene boundary thermal maximum (PETM), which happened about 55 million years ago (see Figures 1, 2 and 4). But the rate of rise surpasses those of this thermal maximum by about ten times.

Figure 3. Plot of percent mass extinction of genera versus peak atmospheric CO2 levels at several stages of Earth history.

Figure 4. The Paleocene–Eocene Thermal Maximum (PETM) represented by sediments in the Southern Ocean, central Pacific and South Atlantic oceans. The data indicate: (a) deposition of an organic matter-rich layer consequent on extinction of marine organisms, (b) lowering of δ18O values representing an increase in temperature, and (c) a sharp decline in carbonate contents of sediments representing a decrease in pH and increase in acidity (Zachos et al. 2008).

The Paleocene–Eocene boundary thermal maximum event about 55 million years ago saw the release of approximately 2,000–3,000 billion tons of carbon to the atmosphere in the form of methane (CH₄). It led to the extinction of about 35–50% of benthic foraminifera (see Figures 3 and 4), representing a major decline in the state of the marine ecosystem. The temperature rise and ocean acidity during this event are shown in Figures 4 and 6.

Based on the amount of carbon already emitted and which could continue to be released to the atmosphere (see Figure 5), current climate trends could be tracking toward conditions like those of the Paleocene–Eocene event. Many species may be unable to adapt to the extreme rate of current rise in greenhouse gases and temperatures. The rapid opening of the Arctic Sea ice, melting of Greenland and west Antarctic ice sheets, and rising spate of floods, heat waves, fires and other extreme weather events may signify a shift in the state of the climate, crossing tipping points.

Figure 5. CO2 emissions from fossil fuels (2.12 GtC ~ 1 ppm CO2). Estimated reserves and potentially recoverable resources.

By analogy to medical science analysing blood count as diagnosis for cancer, climate science uses the greenhouse gas levels of the atmosphere, pH levels of the ocean, variations in solar insolation, aerosol concentrations, clouding states at different levels of the atmosphere, state of the continental ice sheets and sea ice, position of high pressure ridges and climate zones and many other parameters to determine trends in the climate. The results of these tests, conducted by thousands of peer-reviewed scientists world-wide, have to date been ignored, at the greatest peril to humanity and nature.

Continuing emissions contravene international laws regarding crimes against humanity and related International and Australian covenants. In the absence of an effective global mitigation effort, governments world-wide are now presiding over the demise of future generations and of nature, tracking toward one of the greatest mass extinction events nature has seen. It is time we learned from the history of planet Earth.

Figure 6. The Paleocene–Eocene boundary thermal maximum. http://www.uta.edu/faculty/awinguth/petm_research/petm_home.html

Andrew Glikson does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.


This article was originally published at The Conversation. Read the original article.

Andrew Glikson: No alternative to atmospheric CO2 draw-down

by Andrew Glikson, Skeptical Science, February 14, 2013

This article suggests that the current atmospheric CO₂ level is already triggering amplifying feedbacks from the Earth system and therefore, in themselves, efforts at reduction in atmospheric CO₂-emission are no longer sufficient to prevent further global warming. For this reason, along with sharp reductions in carbon emissions, efforts need to be undertaken in an attempt to reduce atmospheric CO₂ levels from their current level of nearly 400 ppm to well below 350 ppm. NASA-applied, outer space–shade technology may buy time for such a planetary defence effort.

The scale and rate of modern climate change have been greatly underestimated. The release to date of a total of over 560 billion ton of carbon through emissions from industrial and transport sources, land clearing and fires, has raised CO₂ levels from about 280 parts per million (ppm) in pre-industrial periods to 397–400 ppm and near 470 ppm CO₂-equivalent (a value which includes the CO₂-equivalent effect of methane), reaching a current CO₂ growth rate of about 2 ppm per year.

Figure 1. Part A. Mean CO₂ level from ice cores, Mouna Loa observatory and marine sites; Part B (inset). Climate forcing 1880–2003. Aerosol forcing includes all aerosol effects, including indirect effects on clouds and snow albedo. GHGs include ozone (O₃) and stratospheric H₂O, in addition to well-mixed greenhouse gases.

Figure 2: Relations between CO₂ rise rates and mean global temperature rise rates during warming periods, including the Paleocene–Eocene Thermal Maximum, Oligocene, Miocene, glacial terminations, Dansgaard–Oeschger cycles and the post-1750 period.

These developments are shifting the Earth’s climate toward Pliocene-like (5.2–2.6 million years ago; mean global temperatures of +2–3 ^oC above pre-industrial temperatures) and possibly toward mid-Miocene-like (approximately 16 million years ago; mean global temperatures +4 ^oC above pre-industrial temperatures) conditions within a few centuries ― a geological blink of an eye.

The current CO₂ level generates amplifying feedbacks, including the reduced capacity of warming water to absorb CO₂ from the atmosphere, CO₂ released from fires, droughts, loss of vegetation cover, disintegration of methane released from bogs, permafrost and methane-bearing ice particles and methane-water molecules.

With CO₂ atmospheric residence times in the order of thousands to tens of thousands years, protracted reduction in emissions, either flowing from human decision or due to reduced economic activity in an environmentally stressed world, may no longer be sufficient to arrest the feedbacks.

Four of the large mass extinction of species events in the history of Earth (end-Devonian, Permian–Triassic, end-Triassic, K–T boundary) have been associated with rapid perturbations of the carbon, oxygen and sulphur cycles, on which the biosphere depends, at rates to which species could not adapt.

Since the 18th century, and in particular since about 1975, the Earth system has been shifting away from Holocene (approximately 10,000 years to the pre-industrial time) conditions, which allowed agriculture, previously hindered by instabilities in the climate and by extreme weather events. The shift is most clearly manifested by the loss of polar ice. Sea level rises have been accelerating, with a total of more than 20 cm since 1880 and about 6 cm since 1990.

For a temperature rise of 2.3 ^oC, to which the climate is committed if sulphur aerosol emission discontinues (see Figure 1), sea levels would reach Pliocene-like levels of 25 meters plus or minus 12 meters, with lag effects due to ice sheet hysteresis (system inertia).

With global atmospheric CO₂-equivalents (a value which includes the effect of methane) above 470 ppm (just under the upper stability limit of the Antarctic ice sheet, with the current rate of CO₂ emissions from fossil fuel combustion, cement production, land clearing and fires of ~9.7 billion ton of carbon in 2010), global civilization faces the following alternatives:

1. With carbon reserves sufficient to raise atmospheric CO₂ levels to above 1,000 ppm, continuing business-as-usual emissions can only result in advanced melting of the polar ice sheets, a corresponding rise of sea levels on the scale of meters to tens of meters, on a time scale of decades to centuries, and high-to-extreme continental temperatures rendering agriculture and human habitat over large regions unlikely.
2. With atmospheric CO₂ at about 400 ppm, an abrupt decrease in carbon emissions may no longer be sufficient to prevent current feedbacks (melting of ice, methane release from permafrost, fires). Attempts to stabilize the climate require global efforts at CO₂ draw-down, using a range of methods, including global reforestation, extensive biochar application, chemical CO₂ sequestration (using sodium hydroxide, serpentine and new innovations), as well as burial of CO₂.

As indicated in Table 1, the use of short-term solar radiation shields such as sulphur aerosols cannot be regarded as more than a band aid, with severe deleterious consequences in terms of ocean acidification and retardation of the monsoon and of precipitation over large parts of the Earth.

In contrast, retardation of solar radiation through space sunshade technology may allow time for CO₂ draw-down. Unlike sulphur dioxide injections, this will not have ocean acidification effects – an effort requiring a planetary defense project by NASA.

Dissemination of ocean iron filings aimed at increasing fertilization by plankton and algal blooms, or temperature exchange through vertical ocean pipe systems, are unlikely to constitute effective means of transporting CO₂ to relatively safe water depths.

In contrast to these methods, CO₂ sequestration through fast-track reforestation, soil carbon, biochar and possible chemical methods such as “sodium trees” and serpentine (combining Ca and Mg with CO2) may be effective, provided these are applied on a global scale.

Such efforts will require an effective planetary defense effort on the scale currently expended on military spending (totaling more than $20 trillion since WWII).

It is likely that a species which decoded the basic laws of nature, split the atom, placed a man on the moon and ventured into outer space should also be able to develop the methodology for fast sequestration of atmospheric CO₂. The alternative, in terms of global heating, sea level rise, extreme weather events, and the destruction of the world’s food sources is unthinkable.

Good planets are hard to come by.

http://www.skepticalscience.com/No-alternative-atmospheric-CO2-draw-down.html

Andrew Glikson: The atmosphere's shift of state and the origin of extreme weather events

by Andrew Glikson, Australian National University, The Conversation, September 21, 2012
Andrew Glikson, earth and
paleo-climate scientist at
Australian National University

The linear nature of global warming trends projected by the IPCC since 1990 and as late as 2007 (see Figure 1) has given the public and policy makers an impression there is plenty of time for economies to convert from carbon-emitting industries to non-polluting utilities.

Paleo-climate records suggest otherwise. They display abrupt shifts in the atmosphere–ocean–cryosphere system, as manifest in the ice core records of the last 800,000 years. This suggests high sensitivity of the climate system to moderate changes in radiative forcing, whether triggered by changes in solar radiation energy or the thermal properties of greenhouse gases or aerosols. In some instances these shifts have happened over periods as short as centuries to decades, and even over a few yearsFigure 1. Global surface temperature rise trajectories for the 21st century under varying carbon emission scenarios portrayed by the IPCC AR4 2007. A2 represents the business-as-usual scenario consistent with currently rising global emissions. (IPCC) Examples of abrupt climate shifts are the 1,470-year-long Dansgaard–Oeschger intra-glacial cycles, which were triggered by solar signals amplified by ocean currents, and the “Younger Dryas” cold interval, which occurred when interglacial peaks resulted in extensive melting of ice and cooling of large ocean regions by melt water. The last glacial termination (when large-scale melting of ice occurred between about 18,000 to 11,000 years ago) is attributed to transient solar pulsations of 40–60 Watt/m2 affecting mid-northern latitudes. This led to a ~6.5+/–1.5 Watt/m2 rise in mean global atmospheric energy level, which meant a mean global temperature rise of ~5.0+/–1.0 degrees Celsius and sea level rise of 120 meters (see Figure 2). Figure 2: Comparison between radiative forcing levels of (1) the Pliocene (~400 ppm CO2; T ~ 2-3 degrees C; Sea level 25+/-12 meters higher than pre-industrial); (2) the last Glacial Termination (~6.5+/-1.5 Watt/m2; ~5.0+/-1.0 degrees C; SL rise 120 meters) and (3) Anthropogenic 1750-2007 warming (1.66 Watt/m2 + 1.35 Watt/m2 – the latter currently masked by sulphur aerosols). Modified after Hansen et al 2008
As shown in Figure 2, anthropogenic carbon emission and land clearing since 1750 have raised the atmospheric energy level by +1.66 Watt/m2. Once the masking effect of industrial sulphur aerosols is taken into account. This totals ~3.0 Watt/m2, namely near half the radiative forcing associated with the last glacial termination.

Compounding the major rise in radiative forcing over the last ~260 years is the rate of greenhouse gas (GHG) rise. This has averaged ~0.5 ppm CO2 per year since 1750. That’s more than 40 times the rate during the last glacial termination, which was 0.012 ppm CO2 per year. The current CO2 rise rate – 2 ppm a year – is the fastest recorded for the Cainozoic (the period since 65 million years ago) (see Figure 3).Figure 3. Relations between CO2 rise rates and mean global temperature rise rates during warming periods, including the Paleocene–Eocene Thermal Maximum, Oligocene, Miocene, glacial terminations, Dansgaard–Oeschger (D-O) cycles and the post-1750 period.(Glikson) We have seen this scale and rate of radiative forcing, in particular since the 1970s, expressed by intensification of the hydrological cycle, heat waves and hurricanes around the globe. It imparts a new meaning to the otherwise little-defined term, “tipping point.”

Between 1900 and 2000, the ratio of observed to expected extremes in monthly mean temperatures has risen from ~1.0 to ~3.5. From about 1970 the Power Dissipation Index (which combines storm intensity, duration, and frequency) of North Atlantic storms increased from ~1.0 to ~2.7in accord withtropical sea surface temperatures which rose by about 1.0 degree Celsius.

Coumou and Rahmstorf (of the Potsdam Climate Impacts Research Institute) state:

The ostensibly large number of recent extreme weather events has triggered intensive discussions, both in- and outside the scientific community, on whether they are related to global warming. Here, we review the evidence and argue that for some types of extreme — notably heat waves, but also precipitation extremes — there is now strong evidence linking specific events or an increase in their numbers to the human influence on climate. For other types of extreme, such as storms, the available evidence is less conclusive, but based on observed trends and basic physical concepts it is nevertheless plausible to expect an increase.

Hansen et al. analysed the distribution of anomalous weather events relative to the 1951–1980 base line, displaying a shift toward extreme heat events (see Figure 4). The authors observe:

hot extreme[s], which covered much less than 1% of Earth’s surface during the base period (1951–1980), now typically [cover] about 10% of the land area. It follows that we can state, with a high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming because their likelihood in the absence of global warming was exceedingly small.

Figure 4. Hansen et al. (2012) calculate the seasonal mean and standard deviation at each grid point for this period, and then normalize the departures from the mean, obtaining a Gaussian bell-shaped distribution. They plot a histogram of the values from successive decades, getting a sense for how much the climate of each decade departed from that of the initial baseline period. The shift in the mean of the histogram is an indication of the global mean shift in temperature, and the change in spread gives an indication of how regional events would rank with respect to the baseline period. 

The consequences for the biosphere of accelerating climate change are discussed by Baronsky et al. in the following terms:

Localized ecological systems are known to shift abruptly and irreversibly from one state to another when they are forced across critical thresholds. Here we review evidence that the global ecosystem as a whole can react in the same way and is approaching a planetary-scale critical transition as a result of human influence.

Climates found at present on 10–48% of the planet are projected to disappear within a century, and climates that contemporary organisms have never experienced are likely to cover 12–39% of Earth. The mean global temperature by 2070 (or possibly a few decades earlier) will be higher than it has been since the human species evolved.

At 400 ppm CO2, potential climate conditions have reached levels which last existed in the peak Pliocene epoch (5.3-2.6 million years ago). Given an increase in extreme weather events under conditions of +0.8 C, an even higher rate of extreme events is expected under conditions of +2.0 C currently shielded by industrially emitted sulphur aerosols.

Current trends in the frequency and intensity of extreme weather events are evident globally (see Figure 5). In the USA, the number of meteorological, hydrological and climatological events rose from about 20-40 per year during 1980-1988, to about 40-80 per year during 1989-2005, to between 70-100 per year after 2006, consistent with global rise in the frequency of extreme weather events.

Figure 5. Global frequency of natural disaster impacts and associated human and economic losses from the 1970s to 1990s. (World Meteorological Organization, 2006) http://www.nrcan.gc.ca/earth-sciences/climate-change/community-adaptation/assessments/378

James Hansen states:

There is still time to act and avoid a worsening climate, but we are wasting precious time. We can solve the challenge of climate change with a gradually rising fee on carbon collected from fossil-fuel companies, with 100% of the money rebated to all legal residents on a per capita basis. This would stimulate innovations and create a robust clean-energy economy with millions of new jobs. It is a simple, honest and effective solution.

New solar technologies promise to provide a large part of the answer. Time is of the essence.

Andrew Glikson is Honorary Professor at the Geothermal Energy Centre of Excellence, The University of Queensland, and a Visiting Fellow at the Australian National University.
http://theconversation.edu.au/the-atmospheres-shift-of-state-and-the-origin-of-extreme-weather-events-9285

Andrew Glikson: Trends and tipping point in the climate system: portents for the 21st century

Trends and tipping point in the climate system: portents for the 21st century 


Andrew Glikson (Earth and Palaeo climate science , Australian National University )

Mass extinctions in the history of Earth occurred when the  atmosphere-ocean-land carbon and oxygen cycles, on which the  biosphere depends, have been perturbed at rates to which species could not adapt. Rising atmospheric greenhouse gas levels above  330 ppm CO2 at rates of ~2 ppm/year and mean temperature rise of ~0.02 oC/year since 1975 and 1976 are driving the fastest climate change trend recorded since about 34 million years ago,  representing a critical climate threshold leading into uncharted  territory and threatening the biosphere and human civilization. It is suggested the arrest of carbon emissions may not be sufficient to  halt the current trend, except if accompanied with global efforts at drawdown of atmospheric CO2 using a range of bio and sequestration,  organic and chemical methods.

Andrew Glikson: As emissions rise, we may be heading for an ice-free planet

As emissions rise, we may be heading for an ice-free planet

by Andrew Glikson, The Conversation, January 18, 2012

An ice-free world isn’t impossible – even though it seems the stuff of science fiction. Alistair Knock.

Last December’s meeting of the American Geophysical Union featured three of the world’s leading climate scientists: James Hansen (NASA’s chief climate scientist), Elco Rohling (National Oceanography Centre, Southampton) and Ken Caldeira (Stanford School of Earth Science). But it was Hansen who attracted the most attention when he stated:

“If you doubled CO₂, which practically all governments assume we’re going to do, that would eventually get us to the ice-free state” and “We would be sending our climate back to a state we haven’t adjusted to as a species."

Reaching ice-free-Earth conditions due to the addition of a few hundred parts per million CO₂ may sound like a science fiction story. But Hansen’s statement is consistent with the natural laws of physics (the Planck, Stefan-Boltzmann and Krichhoff laws of black body radiation), with atmospheric science and with the geological record.

A planet’s surface temperature is determined by the infrared absorption/emission characteristics of its atmosphere, determined by greenhouse molecules (CO₂, CH₄, N₂O, O₃). Earth’s surface conditions (including the atmospheric pressure, temperature and gases in its atmosphere) occupy an intermediate position between those of Mars and Venus. Advanced life on Earth is controlled by the presence of water and by the carbon and oxygen cycles.

Figure 1. CO2 with time. Andrew Glikson (with thanks to D. Royer)

Click to enlarge

Studies of the evolution of the terrestrial atmosphere based on multiple proxies (carbon isotopes in phytoplankton and in fossil soils, plant leaf stomata pores, boron isotopes, boron/calcium ratios) confirm the upper stability boundary of the Antarctic ice sheet at about 500+/-50 ppm CO₂. Other estimates suggest 615 ppm CO₂ or near-800 ppm CO₂.

The original decline in temperature from the end-Eocene (~34 million years ago) and the onset of the Antarctic ice sheet occurred when CO₂ levels declined to below ~600 ppm (as shown in Figure 1). Greenhouse gases have increased by near 40% since 1750 (from ~280 to 392 ppm CO₂, at a rate increasing to ~2.6 ppm/year by 2010). At the current rate of increase, the climate could return to greenhouse Earth conditions within 50 to 200 years.

With current emissions growing by 5.9% in 2010 (see Figure 2) and a corresponding rise of temperature by 6.2% during the last decade (see Figure 3), Earth may be committed to an ice-free state.

Figure 2. Fossil fuel and cement CO2 emissions in billion tons carbon per year (from Think Progress).

Click to enlarge

Figure 3. Percentage change in global average temperature since the 1860s by decade (from the World Meteorological Organization).

Click to enlarge

Climate change projections are complicated by the extreme rates of these processes. There is no precedent for such rates in the geological record, bar major greenhouse gas release triggered by methane eruptions, volcanic eruptions and asteroid impacts.

Further warming of the Greenland ice sheet and of the west and east Antarctic ice sheets may lead to pulses of ice-melt water which will cool adjacent ocean basins. Such pulsations occurred repeatedly in the North Atlantic Ocean around 8.2 thousand years ago (the Holocene Optimum), 12.9-11.7 thousand years ago (the “Youngest dryas” cold phase), and cold phases associated with the peak of earlier interglacials.

The bulk of the continents continue to heat, due to a rise in greenhouse gases, feedbacks from fires, methane release from permafrost and reduction of CO₂ intake by warming oceans.

The resultant ocean-land temperature polarity generates storms, reflected in the title of James Hansen’s book, “Storms of My Grandchildren.” Similar conditions developed in November 2010 as north Siberia and Canada warmed to above 4 °C relative to 1951-1980 while snow storms occurred in the North Atlantic.

Figure 4. Surface temperature Goddard Institute for Space Studies, NASA.

Click to enlarge

The current consequences of polar temperature rises by 4 °C and higher (see Figure 4) for the Greenland and the Antarctic ice sheets are shown in Figure 5. Between 2002 and 2008 a total of near-2500 billion tons of ice was lost, while the projected rate of mass loss nearly doubled over the period.

Figure 5. Ice mass changes http://forum.gloresis.com/2011/06/05/paleoclimate-implications-for-human-made-climate-c/

Click to enlarge

As atmospheric CO₂ is reaching a level unknown for the last three million years, the disconnection between science and the human response is growing. Despite warnings over the last 30 years, we are still developing global infrastructures to extract every economically accessible ton of coal, barrel of conventional or shale/sand oil and cubic meter of natural gas and coal-seam gas.

Contrarian claims by sceptics, misrepresenting direct observations in nature and ignoring the laws of physics, have been adopted by neo-conservative political parties. A corporate media maintains a “balance” between facts and fiction. The best that governments seem able to do is devise cosmetic solutions, or promise further discussions, while time is running out.

Good planets are hard to come by.

http://theconversation.edu.au/as-emissions-rise-we-may-be-heading-for-an-ice-free-planet-4893