Subscribe: Comments for RealClimate
Preview: Comments for RealClimate

Comments for RealClimate

Climate science from climate scientists...

Last Build Date: Tue, 25 Jul 2017 02:13:44 +0000


Comment on Unforced variations: July 2017 by t marvell

Tue, 25 Jul 2017 02:13:44 +0000

I don't know if anyone has referenced this NYT piece: It argues that climate scientists should emphasize worse case forecasts. It is my belief that climate scientists have long been too moderate in their forecasts and too optimistic in their hopes that current actions by world governments will address the problem.

Comment on Climate Sensitivity Estimates and Corrections by t marvell

Tue, 25 Jul 2017 01:58:11 +0000

The ESS has a problem in that it assumes temperature changes are linear, whereas they have been exponential in recent times. The ESS for CO2 is the number of degrees rise in temperature for a doubling of CO2. The better measure is the percent rise in temperature for a doubling of CO2 - in other words, the elasticity. This is especially important when comparing CO2 growth to temperature growth in the past century, and when looking at the lagged effect of CO2 on temperature (and there is a lag of decades). By a statistical artifact, the ESS becomes much larger the longer the lag (because the longer lag gives time for temperature to increase at an accelerated pace). In other words, the ESS is not useful for calculating the impact of CO2 growth on temperature. Thus one should use the elasticity. I calculate an elasticity of .014 for the impact of CO2 growth on temperature (degrees in Kelvan). A recent 25% increase in CO2 translates into a .35% increase in temperature, or one degree. It is risky to extrapolate this beyond recent experience, but it is interesting to note that a doubling of CO2 would thus lead to a 1.4% increase in temperature, or about 4 degrees.

Comment on Unforced variations: July 2017 by nigelj

Mon, 24 Jul 2017 22:44:38 +0000

Zebra @318, you talk in riddles, or maybe I'm just slow on the uptake on this issue. Are you saying capitalism is about money and the freedom to hire labour etc, and operate industries, but certain resources should be owned and controlled by the state, like oil? And presumably better controlled? The state already owns basic resources, and gives extraction rights, and none of this has solved the climate change problem. I don't oppose state ownership of some things because sometimes it does make sense but I'm not sure state ownership of oil would guarantee a particular environmental result. It might help I suppose as people like the Koch brothers would not have a s much power. I think its all more about needing carbon taxes, promoting renewable energy,etc and this is ultimately a political style problem.

Comment on Unforced variations: July 2017 by nigelj

Mon, 24 Jul 2017 22:27:22 +0000

Tony Weddle @317 I accept that true sustainability means zero growth. But true sustainability doesn't make much sense to me, and is too harsh. It's also important to lift people out of dire poverty and some growth will help that process. I think we can have a practical form of near sustainability, and some growth for decades yet without significant environmental damage. Its about methods, management and rules and if anything is more of a political problem. Obviously infinite growth is impossible. This is how I see the challenges in more specific terms: We are looking at an increase in population from the current 7 billion about 10 billion later this century, and this will likely stabilise around there, so we are told. That's what the planet will have to deal with. We already have enough food in the world to feed vastly more people. The problem is waste. Sensible, earth friendly agriculture will get close enough to sustainability to resolve the rest off the problem and it appears capable of increased levels of output to at least some degree short term. I think It would not be capable of ever increasing output longer term but that odesnt matter as long as it feeds global population which will stabilise at around 10 billion, or only grow very slowly from there. Of course reducing nitrate use is very challenging without also reducing growth. But we can at least try to develop alternatives. Clean water and water conservation, etc, are perfectly achievable if there is a will to do this. Ditto with fisheries conservation and quota management. Its more of a political problem. Most people are adequately housed apart from the poor and third world. Building materials can be responsibly extracted and used in increasing quantities for a long time yet without causing serious degradation, if properly managed with proper rules. Of course it cannot grow forever, but it can grow for decades yet. And remember population will stabilise at around 10 billion. Renewable energy is by definition sustainable at least as far ahead as we can reasonably contemplate. Please not this has not decreased rates of gdp growth in America. Consumer goods are a big challenge. We have problems with plastics in the oceans etc. But there are alternatives that are at least semi sustainable. Metals can also mostly be recycled. We can probably increase output of consumer goods for decades yet, but granted not indefinitely. We will eventually have to recycle in a huge way. But by then population will hopefully have stabilsed.

Comment on The climate has always changed. What do you conclude? by Kevin McKinney

Mon, 24 Jul 2017 21:55:43 +0000

On the economics of switching to renewable energy:
As countries consider options at their disposal, understanding the socio-economic benefits of the transition to a renewable energy future is of vital importance. Renewable Energy Benefits: Measuring the Economics provides the first global quantification of the macroeconomic impacts of renewable energy deployment. It finds that doubling the share of renewables by 2030 would bring a range of positive impacts including an increase in global gross domestic product (GDP) up to 1.1 percent, improvement of global welfare by 3.7 percent and over 24 million people working in the renewable energy sector...

Comment on The climate has always changed. What do you conclude? by CCHolley

Mon, 24 Jul 2017 21:55:19 +0000

Victor @97
What evidence do you have in mind? What I keep seeing is evidence the Earth is now warmer than it was 150 years ago. There is plenty of evidence that this is so, and I’ve rarely read anything by any “denier” that argued otherwise. There is also evidence suggesting that warming beyond a certain point could be harmful or even extremely harmful. I see plenty of that sort of evidence, hyped on a daily basis by the mainstream media. I have my doubts on that score, but who knows? As far as evidence for CO2 emissions as a significant cause of the warming, sorry but I see precious little of that. Unless you consider the long list of what amount to excuses for the lack of correlation between CO2 levels and warming as evidence. Back in 2014, that list was already up to 66. ( And that covers only the “hiatus” since 1998. What about the even longer hiatus from 1940-1979? Is that what you call evidence? The introduction of one theory after another to account for the LACK of evidence? In flagrant violation of Occam’s Razor?
What evidence do I have in mind? Very curious that after all the time you spend writing on this site you still do not know the evidence behind AGW. Perhaps you should try reading the science as presented by the founders of this site and take advantage of the various reference links provided. But then again, perhaps not, that would take away your only possible tactic, an argument from your ignorance. And no, I am not referring to any of your spurious claim of theories to account for a so called lack of evidence because as I stated before, there is significant and robust scientific evidence. You also need to rethink Occam's Razor, because you clearly do not have a clue how to apply it.

Comment on The climate has always changed. What do you conclude? by nigelj

Mon, 24 Jul 2017 21:11:46 +0000

alphagruis @112 "Well there might be “plenty of evidence that we have to stop using fossil fuels” yet this does by no means provide any evidence that 100 % (and even 80 %) renewables must in any way be a possible alternative for powering a civilization of 7+ billion people" I disagree. Have a read of "cost of electricty by source" on wikipedia which is the levelised cost, for a large range of specific countries. It's highly detailed and specific with all sources of data cross referenced. If you don't like wikipedia, then Forbes are a business magazine, and have done articles coming up with much the same results. Britanicca is much the same. Dozens of sources will tell you much the same. Summarising things, wind power is now one of the cheapest forms of electricity, often cheaper even than coal. Costs of solar are similar to nuclear and hydro, geothermmal, but falling fast, and are projected to fall further. The most expensive power is generally gas So your claims are just wrong. Jacobson has done a large study showing how renewable energy is viable in virtually all countries. However there is also the nuclear option which is low emissions, which might suit some countries. From your post :"You can even show that switching to renewables from fossil fuels will grow the global economy and improve people’s health and well being.No, that’s just wishful thinking. Nobody “can even show this” and it most likely plainly violates the laws of physics. No wishful thinking might ever change the latter." Coal and gas are implicated in various lung diseases and heart disease. Renewable energy is cleaner. Renewable energy is already creating quite a lot of jobs, far more than traditional forms of energy as below:

Comment on The climate has always changed. What do you conclude? by nigelj

Mon, 24 Jul 2017 20:33:57 +0000

Thomas @109, yeah, I think climate sceptics fall into two broad groups. The first group is ordinary people, and we all have some healthy scepticism of new ideas, but are open to persuasion. If you explain things they see reason, eventually. The second group are the stubborn, longer term denialists. When I read their rhetoric it often emerges that they have strong political views, strong ideologies, vested interests, various chips on their shoulders. Its not unreasonable to conclude this colours their views of the science. This group are harder to convince and stubborn. Warmists come across as more laid back and less rigid in their politics.

Comment on Joy plots for climate change by Steven Emmerson

Mon, 24 Jul 2017 20:15:51 +0000

My God! The distributions in the first graphic crawl!

Comment on The climate has always changed. What do you conclude? by Mal Adapted

Mon, 24 Jul 2017 19:22:51 +0000

MA Rodger:
Mal Adapted @101, I agree with your comment but would put it differently.
While that's by no means unflattering, I'll diffidently point out that I linked leprechauns in toward the end of my comment. That's OK, I don't always read to the end of your comments either. On the whole, your last one was fine 8^D!