It seems to me the proper answer to "When and how bad?" has to be "Depends - on the problem's scope, and on what we do about it." That there are things to be done that are commensurate with the problem seems to me obvious - though I accept this may be a minority view on ASI at present.
The problem's scope is already daunting for many, and while it is not an elephant at six inches, I'd well agree it's an elephant not very far away. My perception of it is from two main perspectives.
First as an activist, having attended and infiltrated the first UNFCCC COP in Berlin, and first being accredited for the following year's COP in Geneva to deliver a paper to delegates on "The Migration of Rainfall" for GCI.
Second as a countryman, with a particular interest in forestry taken to the extent of first consulting to government in '87, and also in farming, which led to my taking on a hill farm in Wales in 2006 of about 120 acres of pasture and 40 of coppices and a couple of square miles of mountain grazing rights.
As a countryman I'd say that the British temperate climate began to decay noticeably in the '70s, and has been destabilizing at a varying pace ever since. As a farmer I've seen several extreme droughts and have been unable to make hay here for the last three summers owing to deluges starting before it was ready to cut, and lasting into September. Previously, losing a hay crop was a once in a generation misfortune up here. A further pressure on traditional farming (which is little more resilient than the 'subsistence' version) is that feed prices have gone from extortionate towards ruinous, to the point that keeping a ewe through winter costs more than the profit from her lamb next autumn.
The latest blow to hill farming was the cold wave that hit in late March as a blizzard and deep frost, and lasted through much of April. When it hit officialdom admitted that 250,000 ewes were killed across Wales alone, with many more expected once the drifts melted. This figure was then withdrawn and replaced with 50,000 overall. The consensus locally is that around 500,000 ewes were killed in Wales, and more than that of their lambs.
Hits on this scale, that rarely attract international media, are occurring with increasing frequency worldwide. And for every such hit there are a number of poor to bad years that lack their drama, and so are discounted. But this is the real decay of global agriculture, in which a Thai flood or a Russian heatwave are the punctuation marks that attract grudging media attention, and no integrated analysis of the trend.
As an activist, I'd point out that a decent regional analysis was provided in the recent study by a Leeds Uni team, led by an IPCC lead author, called "Food Security: Near future projections of the impact of drought in Asia" which is available online in the 'reports' section at:
www.lowcarbonfutures.org.
Quotes from the press release:
"Research released today shows that within the next 10 years large parts of Asia can expect increased risk of more severe droughts, which will impact regional and possibly even global food security. On average, across Asia, droughts lasting longer than three months will be more than twice as severe in terms of their soil moisture deficit compared to the 1990-2005 period. This is cause for concern as China and India have the world’s largest populations and are Asia’s largest food producers.
Dr Lawrence Jackson, a co-author of the report, said: "Our work surprised us when we saw that the threat to food security was so imminent; the increased risk of severe droughts is only 10 years away for China and India. These are the world’s largest populations and food producers; and, as such, this poses a real threat to food security."The fact that Munich Re's 40yr database of catastrophic weather impacts shows that they're rising faster in the USA than any comparable region of the planet, to me implies that without commensurate mitigation we are around a decade away from the start of mega-famines - and the geopolitical destabilization that will generate. NCAR's report on global PDSI to 2090 by Algui Dai gives a timeline of the changes and a graphic that I wish I could post (if anyone else can, I'd be grateful). It projects that by the 2030s agriculture is finished around the Med, and has largely stopped in the US, with various other regions also hard hit.
The certainty of mass migration can be seen in the fact that it has already begun, first from crushed subsistence farms to shanty towns worldwide, and thence to wealthy nations. Notably Central America and Mexico are worse hit than the US, meaning that a proportion of 160 million people are heading north. Just how angry US Latinos get at talk of mining the border is an open question, but I rather doubt the US people would tolerate famine camps and mega-deaths just beyond the fence.
Personally I'd put the start of the climatic destabilization of geopolitics much earlier than the Arab Spring, and perhaps earlier than the grinding multi-year Afghan drought that drove myriads of farm boys into the Taliban to try to support their families. That geopolitical destabilization is clearly progressing, and the further it does so, the more fraught the difficulty of achieving the global collective effort that is pre-requisite for the commensurate mitigation of AGW.
By my count we are many years past the point where Emissions Control alone could resolve the problem. With 0.8C realized, and 0.7C timelagged in the pipeline, and at best 0.6C from emissions' phase-out by 2050, we're committed to 2.1C of warming. But Hansen and Sato found that ending our cooling fossil sulphate emissions unveils another 110% (+/-30%) which would thus give around 4.4C in the 2080s after the 30yr timelag. This in turn would allow about 70yrs of continuous anthro-warming for the interactive feedbacks to accelerate beyond the possibility of control. This is plainly a terminal outcome, despite the successful operation of a quite stringent Emissions Control treaty.
Deploying a global Carbon Recovery program in addition is entirely feasible, but even on a maximum practical scale (limited by the 1.6GHa.s of non-farmland available for native afforestation for biochar) the lead time implies that we'd be doing well to peak airborne CO2 in the 2040s with a slow fall to 280ppm early next century. While this would reduce the peak and duration of ocean acidification, it would do nothing effective to halt the loss of agriculture, and of forestry, or to halt the acceleration of the feedbacks.
The essential complement is thus Albedo Restoration, which Prof Salter (with 30 yrs of Wave Energy tech design and 15yrs of Cloud Brightening research) points out would restore the pre-industrial temperature within two to three years. The three options of Emissions Control, Carbon Recovery and Albedo Restoration can neither function effectively individually nor as any pair in combination; only the three options operating in concert can provide a commensurate mitigation of our predicament. Strangely some of the opponents of Geo-E insist on ignoring this very obvious fact, however often it gets repeated.
The international politics of climate have been thoroughly veiled from the public from the outset, not least by the lie that the IPCC (whose advice the UNFCCC must negotiate from) provides the scientific consensus - when in truth it yields the lowest common denominator of national govts' preferences for public information. Numerous myths have been pushed as received wisdom - that renewables can save the planet (despite any fossil fuel displaced being bought and burnt elsewhere) that the fossil lobby dictates US climate policy (despite providing just 8% of US GDP) and that the denialists fetter Obama from taking action (despite his steadfast obstruction of the treaty being far beyond their reach).
Seen from within the negotiations it is very bloody obvious that US govts since 2000 put maintaining global economic dominance before climate mitigation, knowing that delay raises the threat to China of crop failure, shortages and civil unrest leading to regime change. It might be claimed that this effect is only accidental, but if so, then America is perhaps the first empire in history to be destabilizing its rival's food supply by accident.
Yet with the US getting hammered by climate impacts to the extent that last year they cost most of US GDP, and with finances so tight that the budget for fighting wildfires is cut even as fire projections rise, the outcome of the superpower rivalry is far from settled. It is perfectly feasible that diehards will be ejected due to a mutual realization by cooler heads that the brinkmanship is a lose-lose game.
In that event, the long propaganda since 2000 that "negotiations can't resolve anything" will be exposed as a lullaby for the gullible. With Carbon Recovery offering an equitable and verifiable means of nations clearing their historic emissions by an agreed date, the primary obstruction to agreement is removed. With the prospect of Albedo Restoration (after duly supervised research) rapidly ending climate destabilization, the global South is no longer facing open ended catastrophic climate impacts, and the global North is no longer facing open ended liability for its majority share in the causation of those impacts. The prospect for the adoption of an equitable and efficient framework for mutual commitments is thus transformed.
An unusual feature of the two polar outcomes possible - collective global mitigation or general global collapse - is that there is so little chance of intermediate outcomes. If we fail to halt the famines we lose the geopolitical stability essential to the operation of a climate treaty. If we fail to halt the feedbacks, we lose the possibility of any organized food production.
Getting the decision made to overturn the brinkmanship of inaction will in my view take implacable public pressure on the centres of power. Raising that public pressure is assisted by rising climate impacts, but massively undermined by those who feel the need to declare their defeatism. If they actually give a damn for other people or for the ecosphere they'll recognize that in time of war voicing defeatism is called 'giving aid and succour to the enemy', and they will learn to conceal their doubts while talking up the chances of success.
And that is really the bottom line - if we pull together, globally, as committed ordinary people, we can still resolve the predicament. If we leave it to nationalist politicians and their corporate backers, we shall almost certainly lose the planet's habitability.
Regards,
Lewis