Climate Emergency and the Geologic Record
To expand on prior post #12 , Climate crisis is cultural, the news today is rife with arguments and counter-arguments about climate change, human intervention, and climate emergency for some regions of the world — low lying coastal regions susceptible to flooding by sea level rise, inland areas with more extreme heat and dryness susceptible to fires especially in wooded areas, which disrupt not only human activity but also nature’s carbon cycle — we attempt here to instill some factual base and provide tools to see it.
Pointek et al. highlight the highest risk impact zones for climate change by studying sectors and their overlaps in hot-spots. They not only detail the warnings of COP24 and USGCRP but they also indicate many areas were indicate 4 degrees increase, double the targets to mitigate climate change effects, and that uncertainties make climate change modeling hard to make predictions from. One co-author Friend (pers. comm.) said:
It’s known that 1/3 of the sink exists on land, but the mechanisms are not fully understood. It is the sink of anthropogenic carbon emissions, which has to be a combination of the atmosphere, oceans, and land. The land sink helps reduce the long-term (decadal) build up of anthropogenic CO2 in the atmosphere, and thereby mitigates climate change.
This is an extremely complex area. To reduce it to something more tangible, let’s consider Arctic glacial melt models and predictions against actual measurements. Overland et al. indicate the polar ice cap is shrinking, how they model future shrinking and the uncertainties in such models. The figure below from the paper above shows that actual measures (black) of same are actually worse than the most pessimistic models (in colour)!
Price observed exactly thirty years ago, that erosion from human activity exceeded that from natural processes. Hansen testified a year earlier that he was “99% certain” greenhouse gases were caused by humans, to use pre-climate-change terminology. A lot of ink has flowed on this topic since — indeed Frank Oldfield helped start the Anthropocene Review just to cover that — but to pick only one, Steffen et al. established the human influence in what Crutzen & Stoermer (go to p.17) called the Anthropocene.
Combined with the alarming bio-geography observations above, COP24 highlighted the possible advent of global species extinctions if current trends aren’t reversed — the currently popular theme of global extinction tipping point in 2020 — see below (in colour) that the geological record shows five phases of global species extinctions since the Precambrian, before when the record is too sketchy (question marks). In fact Mace stated twenty years ago that the current rate of species extinctions puts the recent period in line with previous extinctions (in blue below).
A purported sixth extinction is therefore neither unique to the Anthropocene, nor an outlandish suggestion given the history of reported phenomena pointing to this. Bjornerud stated last year that geology gives us a much-needed but largely unheralded perspective in such matters: Geological sciences have evolved from early statist view — earth processes were slow and progressive via small increments over huge time spans such as the fossil record — to recent catastrophist view — violent events punctuate long periods of stasis, such as volcanic events or asteroid impacts, as in Gould’s punctuated equilibrium — and that knowledge gives a broader framework in which to work out aforementioned scenarios.
Where does that leave the (wo)man in the street, to understand enough and stay informed, to elect officials and encourage policies amidst all of the above, or to engage in civic action when those fail? I stated five years ago in the Anthropocene Review mentioned above that:
Provision of broadly accessible and spatially referenced visualizations of the nature and rate of change in the Anthropocene is an essential tool in communicating to policy makers and to the wider public, who generally have little or no contact with academic publications and often rely on media-based information, to form and guide opinion.
Recently available mapping tools and government data-sets make this possible with some acquired knowledge — below you see the Arctic region lately in the news, with historic tall ship traffic that recorded 18th — 19th c. climate data, historic and current ports, ecological zone models through time and maritime economic zones against a backdrop of modern ocean topography — my blogpost offers case studies and course materials to help acquire that knowledge — in addition MOOC (massive open online courses) offer countless more ways to learn this, together with GIS resources online as well as hands-on courses such as Geovation class I’ll attend this week.
This story map illustrates how ready-made tools can help citizens investigate the hazards in the area and study them for themselves, in order to help them take action. This illustration is last year’s California wildfires, which I experienced to a lesser degree, when we lived east of LA over a decade ago.
Story Map Journal
Call to action
This brief overview of the current status quo, the complexities it entails and the means available to study it points to this: enough information is available for all of us — scientists’ cross-discipline knowledge, government / political and industry / professional persons in charge of running countries and economies respectively, and citizens who are affected by all of this — that intelligent personal decisions can and must be made… based on actual facts not possible presumptions! Only then can we hope to properly address the climate changes at hand. Citizen science can truly empower people around the world to understand their local conditions in a global context. Informed citizens are better equipped to address issues from their constituencies through local government to national institutions.
Update: see blog post on measuring Arctic sea ice extent.