Pages

Pages

Pages

Saturday, May 20, 2017

Climate Scientists

4 Climate Scientists & Their Fears for the Future. ABC Australia. video from youtube




Kevin Anderson

Duality in climate science. Oct. 2015.
The commentary demonstrates the endemic bias prevalent amongst many of those developing emission scenarios to severely underplay the scale of the 2°C mitigation challenge. In several important respects the modelling community is self-censoring its research to conform to the dominant political and economic paradigm. Moreover, there is a widespread reluctance of many within the climate change community to speak out against unsupported assertions that an evolution of ‘business as usual’ is compatible with the IPCC’s 2°C carbon budgets. With specific reference to energy, this analysis concludes that even a slim chance of “keeping below” a 2°C rise, now demands a revolution in how we both consume and produce energy. Such a rapid and deep transition will have profound implications for the framing of contemporary society and is far removed from the rhetoric of green growth that increasingly dominates the climate change agenda.

The hidden agenda: how veiled techno-utopias shore up the Paris agreement. Dec. 2015.

The deepest challenge to whether the Agreement succeeds or fails, will not come from the incessant sniping of sceptics and luke-warmers or those politicians favouring a literal reading of Genesis over Darwin. Instead, it was set in train many years ago by a cadre of well-meaning scientists, engineers and economists investigating a Plan B. What if the international community fails to recognise that temperatures relate to ongoing cumulative emissions of greenhouse gases, particularly carbon dioxide? What if world leaders remain doggedly committed to a scientifically illiterate focus on 2050 (“not in my term of office”)? By then, any ‘carbon budget’ for even an outside chance of 2°C will have been squandered – and our global experiment will be hurtling towards 4°C or more. Hence the need to develop a Plan B.


Well the answer was simple. If we choose to continue our love affair with oil, coal and gas, loading the atmosphere with evermore carbon dioxide, then at some later date when sense prevails, we’ll be forced to attempt sucking our carbon back out of the atmosphere. Whilst a plethora of exotic Dr Strangelove options vie for supremacy to deliver on such a grand project, those with the ear of governments have plumped for BECCS (biomass energy carbon capture and storage) as the most promising “negative emission technology”. However these government advisors (Integrated Assessment Modellers – clever folk developing ‘cost-optimised’ solutions to 2°C by combining physics with economic and behavioural modelling) no longer see negative emission technologies as a last ditch Plan B – but rather now promote it as central pivot of the one and only Plan.
So what exactly does BECCS entail? Apportioning huge swathes of the planet’s landmass to the growing of bio-energy crops (from trees to tall grasses) – which, as they grow, absorb carbon dioxide through photosynthesis. Periodically these crops are harvested; processed for worldwide travel; shipped all around the globe and finally combusted in thermal powerstations. The carbon dioxide is then stripped from the waste gases; compressed (almost to a liquid); pumped through large pipes over potentially very long distances; and finally stored deep underground in various geological formations (from exhausted oil and gas reservoirs through to saline aquifers) for a millennium or so.
The unquestioned reliance on negative emission technologies to deliver on the Paris goals is the greatest threat to the Agreement. Yet BECCS, or even negative emission technologies, received no direct reference throughout the thirty-two-page Paris Agreement. Despite this, the framing of the 2°C and (even more) the 1.5°C, goals, is fundamentally premised on the massive uptake of BECCS sometime in the latter half of the century. Disturbingly, this reliance on BECCS is also the case for most of the temperature estimates (e.g. 2.7°C) ascribed to the national pledges (INDCs) prior to the Paris COP.
The sheer scale of the BECCS assumption underpinning the Agreement is breath taking


Jason Box

Earth's ice is melting much faster than forecast. Here's why that's worrying.

If the past decade of scientific inquiry is any indication, I’d say we are in for more surprises. That notion is further supported by the fact that climate models used to project future temperatures lack key processes that likely reinforce warming or the effects of warming, not regulate it.
Despite decades of progress by many clever scientists engaged with climate modeling, climate models used to inform policymakers don’t yet encode key pieces of physics that have ice melting so fast. They don’t incorporate thermal collapse — ice softening due to increasing meltwater infiltration.
Climate models also don’t yet incorporate increasing forced ocean convection at the ocean fronts of glaciers that forces a heat exchange between warming water and ice at the grounding lines.
Climate models don’t yet include ice algae growth that darkens the bare ice surface.
Climate models don’t yet prescribe background dark bare ice from outcropping dust on Greenland from the dusty last ice age.
Climate models don’t include increasing wildfire delivering more light-trapping dark particles to bright snow covered areas, yielding earlier melt onset and more intense summer melting.
As a result of some of these factors and probably some as yet unknown others, climate models have under-predicted the loss rate of snow on land by a factor of four and the loss of sea ice by a factor of two.
Climate models also don’t yet sufficiently resolve extended periods of lazy north-south extended jet streams that produce the kind of sunny summers over Greenland (2007-2012 and 2015) that resulted in melting that our models didn’t foresee happening until 2100.
While individual climate models come close to observations on this or that piece of the complex big picture, what ends up in global assessment reports intended to help guide policy decisions and national discussions of climate change are very conservative averages of dozens of models that don’t include the latest, higher sensitivity physics.
So, alas, when it comes to ice, how fast it can go and how fast the sea will rise, if I were a betting man, I’d put my money on it going faster than forecast.



No comments:

Post a Comment