The solution denial here is with population scientists. If you have a hose running full blast spraying water all over the place and flinging the hose around at high speed, it makes no sense to demand more towels to clean up the mess. It makes no sense to attempt to grab the whipping end of the hose either. Shut off the faucet first. Then we can discuss cleaning up the mess.
 
In this analogy, carbon emissions are one mess that is pointless to clean up until the source of the problem is dealt with. Demographers have this concept of “desired family size”. The notion is that we need to ensure everyone has access to birth control so that they can achieve their desired family size. Population scientists recognize the problem with exceeding the desired family size. However, why do we have the idiotic notion that somehow billions of individuals achieving their desired family size will result in a manageable population size? Why are population scientists sanguine about the fact that desired family size never includes the impact of another birth on everyone else? Why are population scientists effectively mute on the horrible ignorance on population issues?
 
When I was 10 or so, I told my mother that I wanted a family just like hers; 2 boys and 2 girls. She said “hold on there, if you have more than 2 you are increasing the population”. I said “but my children will die someday and that will reduce the increase I created”. She responded by asking what happens if they have children. I remember my brain working through that and realizing that the population will explode towards infinity. I realized that it was morally wrong to have more than 2. I had no problem at age 10 recognizing that if we all have 3 children, we will explode our numbers, and if we all cannot do it, then it is wrong for me to do it. I also intuitively recognized that everyone has to know this. In 15 minutes of conversation my desired family size went from a totally unsustainable 4 to a sustainable 2.
 
40 years later I am stunned, shocked, and appalled that nothing has happened since then to ensure everyone gets that simple education. Unfortunately it took me another 30 years to realize a second important fact. We humans are already way way overpopulated. After reading Jared Diamond’s book “Collapse” I was thinking about how the Easter Islander’s had been chopping down trees to build boats to capture enough food to feed their population. When the trees were all gone, and the last of the boats were rotten, the food supply dramatically dropped. A huge percent starved to death. I was thinking that if only the Easter Islanders had figured out what the Tikopeans had figured out (see the book), they wouldn’t have allowed their numbers to rise past what can be kept alive using only renewable means. Then it hit me like a ton of bricks. We are doing the same right now. Fossil fuels, uranium, draining the Ogallala acquifer and several other acts of destruction are totally necessary to keep 7+ billion humans alive at one time. If my mother had pointed that out to me, my desired family size would have dropped to 1 or 0. It was just as obvious in the early 1970s, when she taught me about the magic number 2, that our numbers were way way over what can be sustained as it is today.
 
What is not obvious is why this is not obvious. Why aren’t population scientists teaching this? Here’s a fine example of the demented thinking on this topic. Taken from Joel Cohen’s book “How many can the Earth sustain”. “Gever et al. (1986) … simply because we are using certain resources faster than they are replenished does not necessarily mean that we are exceeding our carrying capacity and have doomed ourselves to a population collapse”. What a ridiculous justification to not specify the necessary action to avoid such a calamity! This is like a corporate accountant saying we do not have a debt because we will pay it off. Every self respecting corporate accountant states the current facts and does not attempt to predict the future and use that prediction to alter the report of the current situation. Population scientists go even farther along that ridiculous logic path. They take the past, extrapolate that into the future and use that to alter the statement of today’s situation. We found new energy sources in the past, so we will find them in the future, therefore we aren’t blatantly overpopulated today. OMG, just shoot me.
 
This brings me back to Carbon Dioxide. Yes, we have a huge problem because we are dumping CO2 into the atmosphere. But, a much much worse problem is that we are destroying those resources. We must have those resources to make 7 billion meals per day. Maybe what trips up population scientists such that this is not blatantly obvious is that fossil fuels are not required to make food. We can make say 500 million meals per day without burning fossil fuels. This has been achieved. But we have never made more than say 1 billion meals without burning fossil fuels. We have to recognize that fossil fuels are like stores of food. We are eating the stores of food. We cannot keep our numbers alive without eating that store. Here we are chewing through the stores of food on our ship at sea, and this article is whining about the empty cans that are littering the deck of the ship. How about recognizing the loss of future meals! How about recognizing our moral obligation to reduce the number of mouths in the future? Why aren’t scientists demanding that these facts be taught? Why aren’t population scientists going nuts over this educational omission?
 
One reason I chose a water hose spraying madly above, is to have a violent whip. Grabbing that end is pointless. The whip is controlled at the base and that control drives the end at exponential rate. The response above On behalf of Michael Mielke talks about reducing consumption. This is like trying to reduce the whip action by grabbing the end. The base, the number of children we average, is the only rational place to focus our control.
 
What is going on here? What are population experts thinking? Why can’t population experts comprehend that if we must drain fossil fuel reserves to keep our numbers alive, then we must reduce our numbers? Why can’t population experts comprehend the next logical conclusion; that if we must reduce our numbers, then everyone, yes EVERYONE must know this? Somehow population experts cannot make the obvious leap that these facts must be known by every child so that every child grows up knowing that 1 is the maximum desired family size (until we no longer need to destroy resources faster than they renew to keep our numbers alive.)
 
The problem is not with politicians or corporate executives. The problem is not widespread ignorance of the facts of climate change. The problem is near universal ignorance of the simple concept I learned 40 years ago and the other simple concept I learned 10 years ago. The problem is entirely on the shoulders of population experts for failing to demand that these concepts be taught in every school in the world. Of course politicians are doing nothing about climate change. We need to burn the stuff to keep our numbers alive. Of course politicians are doing nothing about reducing our numbers, they are just as ignorant as the rest of the population. Population scientists need to start teaching.
 

I broadly agree with John Harte. I am worried about emphasis (by Glyn Prins and others, not to mention recent COP talks) on “adaptation” for many reasons. Not least of these reasons is that other species don’t know they’re supposed to adapt! IPCC AR5 WG2 seems to confirm ~50% species loss at 3°C rises and above, although points out it’s the speed of the transition as well as its final size that is important; mangroves swamps and coral reefs may be first to collapse.

Also “adaptation” to climate change is almost inseparable from other development issues around health and agriculture, and doesn’t really affect moral obligations of rich countries to poorer ones. However, the capacity to generate clean energy, transport and cooking by investing in low-carbon infrastructure now could be a mitigation effort that also has massive development (and incidentally, population) benefits and allows much of the world to leapfrog the obsolete dirty infrastructure of Europe and the US.

Geoengineering is certainly taken less seriously than adaptation for good reasons, including the expense and potential for knock-on effects. Not all geoengineering solutions fail to address ocean acidification, but most of those also look impractical. Seeding algae and diatoms with iron should increase carbonate deposition, but doesn’t look effective; circulating deep ocean water is supposed to have similar effect but again would be desperate. However, I’d hate to think scepticism about geoengineering put engineers off looking at solutions: you could argue that reforesting the Sahel, or soil stabilisation, or huge concentrated solar power projects in similar regions are interventionist “geoengineering” in some sense, but they would also be broadly positive mitigation efforts that work in roughly the opposite direction to burning coal, oil, gas and forest.

Incidentally, I don’t really like using the word “mitigation” as it is confusing to many people – I find myself talking about “mitigating the effects of climate change” and confusing myself. I’d rather we talked about “emissions reduction”, afforestation etc to make it clear what measures are needed.

Suposedly, economists are trying to minimise the total cost of “mitigation”/emission measures + adaptation + residual damage. They generally try to do this through Intergrated Assessment Models, the most famous of which is PAGE09. There are obvious massive problems with this, principally as regards putting an economic value on adaptation and damage covered in IPCC WG2, which really only looks at loss of trade, and doesn’t put any value on lost ecosystem services. Economists cannot decide that; it can only be decided politically and ethically.

Some commentators, such as contrarian Bjorn Lomborg, have simply read off figures from WG2 and WG3 to suggest optimal intervention is minimal, not much more than we’re doing now. It’s fair for John Harte to describe this short-sightedness as a “myth”, but of course we should still continue to research and find better ways for the general public to understand these economic calculations.

I do agree (with JT) that industrial agriculture generally produces large quantities of CO2, CH4 and NOx, and reducing amount of food production is likely to be necessary to reduce climate risks to manageable levels. However, besides reducing number of mouths to feed, reducing overconsumption, food wastage, meat consumption and nitrate usage also help this dimension. Similarly, we don’t particularly need to use lime and cement – can we look at organic resins for construction instead? These areas do require large government investment, incentives and social changes, but given those should not require a traumatic population collapse.

In the long term, population reduction, for various resource reasons as well as climate change, is probably inevitable one way or another. However, just like people who want to solve climate change through their favoured radical economic change (eg Naomi Klein), or a spiritual awakening, it’s just too slow. Climate change isn’t itself going to limit population until massive changes are already committed. Human life expectancy of 70 is greater than the life expectancy of carbon-burning infrastructure, which is long enough, and ocean heat content also builds over decades. There’s are many buffers, lags, inertias and lead times to worry about already without getting political consensus over things that aren’t going to start having effect for at least a generation. Societies change slowly, and we need to slow warming now to give a chance for any political, ecological, ethical or economic realisation to sink in.

Kevin Anderson suggests 4 °C above pre-industrial is incompatible with human civilization (and Joseph Tainter and Ronald Wright make the principle of global collapse look plausible). I don’t know, but I do know it would be an ecological disaster, and that the IEA and others have us on that course by 2100. “So we have to mitigate” says John Harte.

OK, here’s my suggestion – nothing new, but I want to push it:

1) Continue with Kyoto/Durban mechanisms around emissions, but with a much more ambitious cap, distributed mostly according to capability, and augmented by bilateral agreements. Kyoto is controversial, partly because it doesn’t seem to have achieved anything, because the CDM has trouble defining “additionality”, partly because its complexity benefits mostly financial interests and actually for many other reasons. But it still has forward momentum from vested interests, Berners-Lee and Clark in _The Burning Question_ suggest a cap is necessary to avoid economic rebound effects. It’s not “the only game in town” as is claimed by any means, but I believe it has at least developed some means of quantifying emissions and can be steered by other policy and social responses to produce economic responses.

2) Besides the various agreements to reduce emissions, incentives need to be introduced in fossil fuel extraction. James Hansen as well as many conservatives favour national “fee and dividend” schemes that would benefit the majority of the population financially – these then need a border adjustment tax on imported fuels or goods, which apparently is permissible under existing WTO rules, which should be clarified. In the UK I believe the Climate Change Levy (effectively a carbon tax on businesses) has begun to make progress. My idea is that the combination of a price intervention at the extraction stage and another at the emissions stage could be mutually reinforcing.

3) Market-based solutions, merely giving a price signal to people about which are more unsustainable goods, is insufficient. People make their choices for complex reasons, and price is insufficient to change social norms. There needs to be far more education about ecological consequences of personal and corporate decisions. The EU energy efficiency label supposedly helps consumers make choices, but only has marginal effect. Once there is increased awareness of ecological as well as financial costs of product lifecycles (running costs), there should be increased popular pressure to ban certain carbon-costly practices, with perhaps pictures of drought-stricken fields on inefficient products, and some banned altogether to encourage better design.

4) The above should also steer private investment, but as Stern described climate change as the biggest market failure in history, governments should be freed and encouraged to also directly requisition resources and invest in green industries domestically and worldwide. Not just renewable generation, but sustainable agriculture and housing. As in a war effort, governments may also need to invest in domestic (explicit and transparent) propaganda to change social attitudes. They’ve done it for smoking tobacco, now they need to do it for combustion generally.

5) Emissions reduction must be seen as a central component to international development. There will also be a need for increased disaster and famine relief, but maybe the Green Climate Fund will ultimately help fulfil this need.

6) Population control policies are more likely to be acceptable and work once we can see ourselves facing global problems, and that’s more likely when it’s harder for those with power to insulate themselves against them, in other words in a more equal world.

7) This is not an exhaustive list, and continual review looking for ecological hazards is needed.

That may sound too prescriptive, but my question is how we multiply the political will to get there, in my estimation by a factor of ten from what we have now.