Showing posts with label methane. Show all posts
Showing posts with label methane. Show all posts

November 11, 2017

Seven megatrends for global warming ‘hope’ – five of which are bunk

At The Guardian on 8 November, Damien Carrington wrote “The seven megatrends that could beat global warming: ‘There is reason for hope’

1. Methane: getting to the meat
2. Renewable energy: time to shine
3. King coal: dead or dying
4. Electric cars: in the fast lane
5. Batteries: lots in store
6. Efficiency: negawatts over megawatts
7. Forests: seeing the wood

#1: Methane not only has >20 times the greenhouse effect of CO₂, it persists in the atmosphere only ~10 years, whereas CO₂ persists for hundreds, ie, the emissions from coal burning in the 19th century are still out there and those from coal and oil in the 20th century and today will not diminish for hundreds of years.

Alas, besides #1, and except for #6 (using less energy), the other points are bunk.

#2: Intermittent and variable renewable energy (wind and solar) do not significantly reduce emissions, because backup sources are required. And such diffuse energy sources require massive amounts of land and materials to collect any meaningful amount: real adverse effects being the cost of theoretical-only benefits.

#3: Coal use is not diminishing, only slowing in growth. Where it has decreased, it is being replaced by cheap natural gas (half the CO₂ emissions but lots of methane leakage at the wells; also most practical backup for wind, except that forces the generators to operate at about half the efficiency they are otherwise capable of).

#4: Electric cars are only as "green" as the grid they get their power from (and see #5).

#5: Batteries reduce efficiency (see #6). For example, an internal combustion engine is a lot more efficient that burning fuel to make electricity (with two-thirds of the energy lost as heat) to charge batteries to then move a car. And like electric cars, they are an environmental disaster on a large scale.

#6: There is a shortcoming here, though, in that demand for energy continues to grow with increasing population and wider technological prosperity (i.e., more of the world living like the richest), offsetting increased conservation and efficiency.

#7: The article calls for rather than cites ending deforestation. It does not mention that much of it is driven by animal agriculture (another, besides #1, of its contributions to climate change). It mentions palm oil plantations, but doesn't mention that those are for "green" biofuel. It doesn't mention the cutting driven by demand for wood as a "green" source of electricity and heat.

Cf:Wind and Solar Power Advance, but Carbon Refuses to Retreat” By Eduardo Porter, New York Times, Nov. 7, 2017

June 30, 2016

The complexities of greenhouse gases

A table of global sources of the three main greenhouse gases – carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O, also abbreviated as NOx) – is reportedly no longer readily available from the UN Intergovernmental Panel on Climate Change. Here it is as reproduced by the US Energy Information Administration in the December 2004 report, “Emissions of Greenhouse Gases in the United States 2003”.


The table shows that human (anthropogenic) CO₂ emissions in the 1990s were less than 3% of the total, ie, 97% of CO₂ emissions were natural, although more than half of the human emissions exceeded the amount that could be naturally absorbed. For the other greenhouse gases, human CH₄ emissions were 50% greater than natural CH₄, representing 60% of the total, and only 6% of the human emissions exceeded what could be naturally absorbed. Human N₂O emissions represented about 55% of that total, and 55% exceeded what could be absorbed.

One thing that the table does not indicate is the different greenhouse effect levels of the three gases. CH₄ has 20 times the greenhouse effect of CO₂, N₂O 300 times. Therefore, the annual increase in greenhouse gases by effect is about 88% due to CO₂, 3% to CH₄, and 9% to N₂O.

Combining that information with what the table indicates, to halt the annual increases in these greenhouse gases, humans would have to reduce CO₂ emissions to 51% of the level specified here for the 1990s, N₂O to 25%, and CH₄ to 94%.

If the annual increase in greenhouse effect were to be halted by reducing CO₂ alone, humans would have to reduce emissions to less than 43% of their 1990s level. If, however, human CH₄ emissions were halved (relatively easy to achieve by, eg, reducing animal agriculture and capturing leakage at natural gas wells), human CO₂ emissions would have to be reduced to 58% of their 1990s level.

Another important consideration is the very different half-lives of these greenhouse gases. Most strikingly, CO₂ persists for centuries, even millennia, in the atmosphere, whereas CH₄ persists for only about 10 years. In other words, changes to CO₂ emissions would not have an effect for hundreds of years, but the effect of changes to CH₄ emissions would be relatively immediate. (N₂O lasts about 100 years.) (It may well be that the climate change effects we are experiencing today are due to coal burning in the 19th century, which at the time was mitigated by the cooling effect of soot.)

In summary, halting the increase of greenhouse gas emissions remains a formidable challenge, let alone that of reducing their levels in the atmosphere. But N₂O and CH₄ are easy targets for reduction that must not be ignored, particularly because their reduction would have a much more immediate effect than reduction of CO₂.

April 25, 2015

Climate science denial of environmentalism

There is great anxiety in certain quarters about convincing "nonbelievers" of the dire truth about anthropogenic climate change.

The desperation of that effort suggests that accepting climate science isn’t in fact the real issue. That’s because there is no reason to question the science, unless one has doubts about what is being done with it.

The fact is that most people in line with the science aren’t doing anything more meaningful about it than people who question the science. Climate science is used mostly as a cudgel to promote new businesses (that are just as harmful to the planet, such as nuclear power, or even more so, such as biofuel) or – perhaps even more importantly – as a distraction from other, usually more immediate, problems that have obvious – but politically more challenging – solutions (eg, climate change is probably the least serious of the threats to The Everglades, but since nobody is directly to blame, nobody has to worry about being forced to actually do anything about it).

A glaring example of the cynical use of climate change – in the win-win-win of politicians and businesses expressing concern while promoting each others’ purely venal interests and of environmental groups taking their cut and keeping membership numbers growing by making it easy to save the planet with mere symbolic gestures. The lack of seriousness regarding climate change is most evident in the acquiescence to animal agriculture. Animal agriculture is conservatively estimated to contribute as much greenhouse effect as all transportation (not to mention its being the leading cause of many other environmental effects, such as deforestation and water depletion and pollution). Furthermore, most of that greenhouse effect is due to methane (CH₄), which persists in the atmosphere a small fraction of the time that carbon dioxide (CO₂) does, so that decreasing it would have almost immediate climate benefit. In contrast, benefits from reducing CO₂ would not be seen for many decades, even centuries. Yet reducing consumption of meat and dairy – which is as easy as switching lightbulbs – is almost never mentioned by those who fight to defend the science of climate change.

Accepting climate science does not make one an environmentalist. It actually often seems to enable a denial of environmental concerns.

Most real solutions to social and environmental problems would also benefit the carbon balance of the atmosphere, so accepting climate science is not actually important. Analogously, one doesn’t have to accept (let alone understand) the science of biological evolution to support protecting species and habitat.

These are culture-war sideshows that only serve business as usual, not positive change.

November 20, 2014

Renewable energy won’t reverse climate change

Ross Koningstein and David Fork, engineers at Google, write at IEEE Spectrum (excerpts):

At the start of RE<C, we had shared the attitude of many stalwart environmentalists: We felt that with steady improvements to today’s renewable energy technologies, our society could stave off catastrophic climate change. We now know that to be a false hope ...

As we reflected on the project, we came to the conclusion that even if Google and others had led the way toward a wholesale adoption of renewable energy, that switch would not have resulted in significant reductions of carbon dioxide emissions. Trying to combat climate change exclusively with today’s renewable energy technologies simply won’t work; we need a fundamentally different approach.

[T]oday’s renewable energy sources are limited by suitable geography and their own intermittent power production. Wind farms, for example, make economic sense only in parts of the country with strong and steady winds. The study also showed continued fossil fuel use in transportation, agriculture, and construction.

RE<C invested in large-scale renewable energy projects and investigated a wide range of innovative technologies .... By 2011, however, it was clear that RE<C would not be able to deliver a technology that could compete economically with coal, and Google officially ended the initiative and shut down the related internal R&D projects. ...

In the energy innovation study’s best-case scenario, rapid advances in renewable energy technology bring down carbon dioxide emissions significantly. Yet because CO₂ lingers in the atmosphere for more than a century, reducing emissions means only that less gas is being added to the existing problem. We decided to combine our energy innovation study’s best-case scenario results with Hansen’s climate model to see whether a 55 percent emission cut by 2050 would bring the world back below that 350-ppm threshold. Our calculations revealed otherwise. Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO₂ levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change ...

Suppose for a moment that it had achieved the most extraordinary success possible, and that we had found cheap renewable energy technologies that could gradually replace all the world’s coal plants — a situation roughly equivalent to the energy innovation study’s best-case scenario. Even if that dream had come to pass, it still wouldn’t have solved climate change.

Incremental improvements to existing technologies aren’t enough; we need something truly disruptive to reverse climate change. What, then, is the energy technology that can meet the challenging cost targets? How will we remove CO₂ from the air? We don’t have the answers. Those technologies haven’t been invented yet.

[And then there's methane, with ~25 times the greenhouse gas equivalence of CO₂ and whose reduction would show effect in only a few years. Go vegan, people.]

November 15, 2014

Comments on the Vermont campaign for a carbon tax

The Vermont Public Interest Research Group (VPIRG) and friends in business and the legislature have proposed a tax on fossil fuels used in heating and transportation, starting at $5 per metric ton (“tonne”) of CO₂ and rising to $50 in 10 years (or $150 in 15 years).

Ninety percent of the revenue would be returned as tax cuts to businesses and households, which would rather nullify the incentive. The concern for reducing the burden on lower-income people is a sham, because getting a tax cut or even rebate in May won’t help to pay for gas or heating oil back in January.

The VPIRG press release trots out hurricane Irene as a warning of future extreme weather due to climate change. That is flat out bullshit. Hurricanes are a normal feature of the weather, and Irene was not even extreme — New Yorkers scoffed at its dissipation. Irene's damage was so great simply because it stalled over the Green Mountains. Climate change — as one part of our general environmental depredation — is a serious issue that is not well served by baseless fear mongering.

Finally, what about the second major greenhouse gas, methane? Besides every one of Vermont’s cows exhaling about 1 tonne of CO₂ per year, each of them also emits methane by belching and farting (not counting that contained in their manure) with a greenhouse gas equivalence of about 7 tonnes of CO₂ per year. With some 150,000 cows in Vermont, that's some serious emissions (1,200,000 tonnes of CO₂ and equivalent: $60 million at the proposed $50/tonne). And ignoring it is a serious omission in any plan claiming to address climate change.

If taxing cows as well as fossil fuel is not an option, how about giving some of the 10% of the revenues earmarked for energy improvements to subsidizing alternatives to animal agriculture. Much like the state makes it cheaper to buy CFLs and LEDs, why not also make it cheaper to buy vegan meat and dairy substitutes?