Life in the Hothouse

“Wetlands are wastelands” was the explanation the chair of a local trust in my city gave for opposing a grant to a wetlands restoration project. He’s a rabid climate change denier and hence unlikely to read Melanie Lenart’s recently published book Life in the Hothouse: How a Living Planet Survives Climate Change. If he did he would discover how wrong he was. Not that he needed wait for her book: it has been evident for many years that wetlands are vital to ecological health. So are forests, which play an equal part in Lenart’s explanation of how Gaia, or, if you don’t like metaphor, the complex interacting system of the biosphere, responds to maintain a temperature within a range suitable for life. A scientist with a background in journalism, Lenart is well placed to provide a coherent account for the general reader of the work of a host of researchers who have explored some of the intricacies of response to warming in Earth’s ecosystems.

She opens with an interesting account of hurricanes as both a symptom of global warming and one of its cures. A warmer world is likely to mean they are more intense. She considers them from the perspective of their cooling function, helping to shift heat away from the tropics. Their destructive power, which is clearly pictured, paradoxically boosts plant life in the sea and on land through sediment stirring and transfer and so aids the drawing down of carbon dioxide from the atmosphere. They also contribute to carbon sinks by burying logs, soil and sediment in landslides, the ocean, and anywhere they can better escape decay.  In these respects they are one of Gaia’s natural defences to rising temperatures.

A chapter on circulation patterns explores many of the ways in which precipitation has increased in warmer climates in the past and considers the contribution of such features as the Hadley circulation between the equator and the sub-tropics. The comparative dryness of the ice ages came as a surprise to climatologists. The evidence Lenart adduces spanning the ice ages to ancient hothouses makes it clear that global precipitation rates increased as the climate warmed. This she sees as helping boost a Gaian response to changing climate, namely increased plant growth.

There follows a survey of carbon dioxide uptake by plants and trees and how various forests fared in past climates.  More carbon dioxide has meant more growth.  More precipitation and more warmth has helped that growth. The contribution of plant life in taking carbon dioxide from the air is significant.  The world’s trees alone hold nearly as much carbon as the atmosphere. In this way life becomes part of the Gaian attempt to regulate temperature.

Soils and wetlands also soak up excess carbon dioxide. Wetlands’ special talent for this is related to their remarkable productivity combined with their slow decay rates. Decay stalls in stagnant waters, including the decay of organic material from far and wide that ends up in wetlands because of their low-lying position.  The world’s soils are considered by some researchers to hold three times the amount of carbon in the vegetation growing on them. Lenart explains in detail how this happens, with coal being the prime example of the process in the distant past: carbon well sequestered until we started to extract and burn it.

Weathering is the final process Lenart considers as another method by which Earth balances its carbon dioxide ledger. It takes place over a long term and is perhaps not likely to be of much assistance in dealing with our present problems, but it’s a fascinating sequence she describes as nature’s version of acid rain works to break down rocks with a resultant carbon storage in the sea – for limited periods in the case of limestone, but more permanently in the case of basalts and granites, at least until it becomes volcano fodder.  Weathering speeds up in hot, humid climates, pulling more carbon dioxide out of the air when there is more than usual there.

I’ve scratched the surface of chapters that are packed with interesting detail about both past and present.  Lenart does an excellent job of pulling together information from numerous studies, often updated by direct communication with the experts involved, and building it into a sustained overall picture. The story is enlivened by some of her own direct experience in forest and desert. The good science writer or journalist is able to render the general reader this service in a way that the specialists engrossed in their work would be harder put to provide.

The book’s strands come together in a chapter titled systematic healing. Lenart fully subscribes to the recognition that our use of fossil fuels must be drastically cut. She’s not suggesting any alternative to that. Her particular interest is rather in how we can also work with the natural systems her book has been describing to help moderate the warming and soften the severity of its impacts. She acknowledges that is difficult in our current economy where the bottom line ignores environmental costs and overlooks environmental services. In fact the services provided to humans by wetlands and forests, including urban forests, go well beyond carbon counting. Urban forests provide shade and evaporative cooling valuable in times of elevated heat.  She refers to the efforts in Chicago to plant rooftops and increase ground tree and shrub planting as an example other cities might follow. Urban greenery not only cuts heat, but provides habitat for birds and other wildlife, insulates against noise, offers recreational possibilities and reduces air pollution including carbon dioxide. There is even some evidence that it cuts crime!

Forests on a larger scale  promote rainfall. Forests and wetlands slow down winds. Wetlands absorb storm surge and slow flooding rivers. They also purify water. Biodiversity and genetic diversity are greatly assisted by wetlands and estuaries. These and many other services are additional to the carbon capture contribution made by forests and wetlands, the protective shield a warming planet produces. Our current experiment is to interfere with the development of these natural protective processes. We are lowering biomass, lowering water tables, lowering the quantities of weathering product reaching the sea through extensive development, logging, groundwater pumping, and river diversion.

Lenart metaphorically shudders at the thought of some of the geo-engineering fixes being proposed. Why build artificial trees to chemically remove carbon dioxide from the atmosphere, she asks, when Gaia can make trees that provide food and shelter, sunscreen and windbreaks, and flood-control and drought-prevention services even while collecting carbon dioxide and other pollutants? She looks to a variety of forest and wetland restoration projects to restore these key systems. The more we can count on forests and wetlands to stabilise the carbon dioxide drawdown, the less pressure we put on oceans to take up the gas and thus increase their acidity. And the more we pull down greenhouse gases into forests, their soils and wetlands, the less need the planet will have for cooling hurricanes and floods. Life gets better at all scales when we boost Gaia’s natural defences.

Ah, I see you have the Wishart that goes “ping”

n Ian Wishart’s lexicon, to “ping” someone seems to mean catching them out in a mistake or false claim. It’s a word he’s fond of using in his regular attacks on Hot Topic, most recently over my post on sea ice volume, and a comment thereunder by William “Stoat” Connolley. My post was “bad science” and I’m a “science illiterate” it seems. Unfortunately, all Ian does is demonstrate that his own science literacy is somewhat limited. His ping, like sonar, comes bouncing right back at him…

 

My post Feel floes (gone by 2016) was mainly concerned with looking at the issue of whether the Arctic sea ice was “recovering” from the record minimum of 2007. Wishart says it is “recovering strongly for the third year in a row”, but the volume data shows that to be nonsense. Wishart’s main bone of contention, however, seems to be about the impact of sea ice reduction on northern hemisphere climate. Here’s his first misdirection:

Gareth, incidentally, tries to argue in reply that volume is relevant because of the heat exchange to the atmosphere involved in re-freezing water.

My reply made no mention of volume versus area — I was just pointing out that albedo effects (though important) are not the only climate impact to be expected from a reduction in sea ice. The last three years have averaged around 2 million square kilometres below the average minimum over 79-00. That huge area of ice has to refreeze in autumn, and in so doing releases heat to the atmosphere. It seems Ian doesn’t have the foggiest how much is involved.

But here’s some news that evidently they missed over at HT: when ice grows in volume, it’s because sea water is converting to solid ice, with the same heat exchange taking place in regards to the first six inches of ice, the next six inches of ice, and all the ice thereafter. And sea ice grows because it is freakishly cold, and what little heat is liberated in the process is not strong enough to compensate for the cold.

Read that last sentence again: “what little heat is liberated in the process is not strong enough to compensate for the cold.” Time for today’s lesson. The heat required to warm 1 kg of water by 1ºC is a little over 4,000 Joules. The heat required to melt 1kg of ice is 333,550 Joules (aka the enthalpy of fusion) — about 80 times as much. The same applies in reverse — that is, when 1 kg of water turns to ice, it releases 333 kilojoules of energy. Now consider how much extra heat (compared with the long term average) is being liberated by the formation of 2 million km2 of new ice, which over winter will become about 1.5 metres thick. It’s a very big number indeed — my back of the envelope calculation (corrections and precisions welcome — William?) suggests it’s of the order of 11.5 x 1011 GJ (gigajoules). A big number. Let’s halve it, to allow for ice acting as an insulator. Still more than big enough to show up in the figures for Arctic climate. And it does.

Wishart dislikes Skeptical Science almost as much as Hot Topic (he describes John Cook as my alter ego, which is much more flattering to me than John). There’s a recent post there about a new paper describing the feedback loop between summer sea ice reductions and autumn and winter warming (also at Science News). But there’s an earlier paper to refer to, that I’ve written about before: The emergence of surface-based Arctic amplification by Serreze et al (The Cryosphere, 3, 11–19, 2009 – PDF) who examined Arctic climate data up to 2007 and found them to be “consistent with the emergence of surface-based Arctic amplification associated with declining sea ice extent”. There’s a good discussion of what this is and what it might mean for climate and weather in Mark Serreze’s chapter in last year’s WWF Arctic report, discussed at Hot Topic here. In any event, it’s not news. You might have expected someone as au fait with the literature as Wishart to have been keeping up. Or perhaps not…

Still, I did learn something interesting from his post. He’s finished his “Climategate” revision of Air Con, and apparently this “new edition also contains extensive new information on why ocean acidification is not being caused by CO2“. Oh really? That’ll be news to the oceanographers of the world. An excellent excuse for another look at his “work”, perhaps… ;-)

[The hospital sketch (bonus audio edit)]

Time of the season

Climate change involves more than straightfoward warming, it also affects the patterns of weather and the seasons, as John Parker discovers in an excellent feature — What’s happened to the seasons? — in the Spring issue of The Economist’s Intelligent Lifemagazine. Parker’s done his homework, and his article is the best overview of recent changes in seasonal weather around the world, and the knock on impacts on agriculture and ecosystems that I’ve read. Here’s a sample:

Some seasons have vanished altogether. In Kashmir there used to be a brief rainy season between winter and spring, called tsonth -— three or four weeks of torrential downpours, bright sunshine and snow on the ground. But, says Rais Akhtar of the University of Kashmir, the state has not seen a tsonth for ten years. The first rainy season seems to have dried up in Uganda. In Ntchenachena, in northern Malawi, villagers used to describe four episodes of rain, each with their proper name and association with particular farming events. Since 2001, they say, the pattern can no longer be discerned.

Parker points to increasing unpredictability in “traditional” seasons posing a challenge to agriculture as well as dislocations in ecosystem linkages. We may even have seen an example of that in the last year in New Zealand. 2009 was a remarkable switchback between hot and cold weather. May was very cold, but August was the warmest in the 155 year record. And temperatures then flatlined through until the end of October, which was the coldest for 64 years. Check out the NIWA summary of the year, or MetService Weather Ambassador Bob McDavitt’s round up at Sciblogs. Perhaps global warming really is turning out to be global weirding.

[Zombies (I used to play for the same cricket team as Colin Blunstone, but never at the same time, unfortunately)]

You don’t know what you’ve got ’til it’s gone

Biodiversity continues its steady decline. A team of scientists have this week published a study in Science confirming that fact.  Governments in 2002 at a summit on the Convention on Biological Diversity agreed to aim to halt biodiversity loss by the year 2010. When experts meet in Nairobi on May 10 it will be to face the news that they have failed.  For example, since 1970  the world’s animal population has decreased by 30%, mangroves and sea grasses have shrunk in area by 20%, and live-coral coverage has fallen by 40%. “The state of biodiversity is definitely showing a rapid decline,” says Matt Foster, one of the lead authors on the Sciencepaper. “And the pressure just keeps increasing.”

It’s not that governments have made no efforts. The amount of protected land has steadily increased around the world, as has the area of sustainably managed forests. Increased money is being spent on biodiversity aid. But we’re still shouldering other species out of our way. And in doing so we’re attacking our own well-being. “We all benefit from biodiversity and we all hurt when it’s lost,” says Foster.

Climate change is only one of the ways in which humankind is contributing to biodiversity loss.  But it’s worth reminding ourselves that it is seriously exacerbating the process. I’ve been re-reading a fine book by Michael Novacek, Terra, published in 2007. He’s a distinguished paleontologist, Provost of Science at the American Museum of Natural History.  He was involved in the splendid Darwin exhibition put together by the Museum of Natural History which I was fortunate to be able to see when it was brought to the Auckland Museum in 2007.  That’s when I bought his book.  It’s subtitled Our 100-Million-Year-Old Ecosystem –- and the Threats That Now Put It at Risk. I think some points from his chapter on how the current warming is contributing to biodiversity loss are worth recounting here.

He notes changes in the activity of 694 species whose life history data between 1951 and 2001 has been studied.  A 2003 review found on average the species were either breeding, blooming, or doing other seasonally related activities 5.3 days earlier each decade.

The warming trend has also set species in motion. Some move poleward. Other species have moved upslope. Some have simply contracted and their surviving, marginalised populations have been reduced to precariously low levels.

Novacek is interesting on the evolutionary processes at work in the organisms affected by rapid alteration of range. The hardy colonisers which often establish at the leading edge of the shift may have a very low level of gene diversity, leaving them susceptible to further environmental changes. The populations at the trailing edge of the migration may have more genetic diversity, but they will start to fragment as the environmental conditions break up their preferred habitats.  The rate of environmental challenge may determine how a population’s genetic makeup and evolution are transformed. Slow change may be easier for the species to maintain genetic diversity at levels that allow it to persist. Drastic and rapid change make it more vulnerable. Simply moving to a cooler habitat does not guarantee that the genetic composition of the migrating populations will be robust enough to sustain them.

It’s made more complex by the bewildering diversity of examples in nature. Some species, especially in tropical and mountainous regions, may be buffered by the amount of genetic variation already resident in their populations. Other genetic studies suggest that climate change has easily outrun the rate at which a given population can adjust.

Novacek  sees contemporary evidence that climate change in combination with other factors is killing off certain species.  It seems to be the coup de grace for some coral species.  Increasing ocean acidification also plays a part in the demise of coral and threatens the most abundant and ecologically important sea organisms, the coccolithophorids, foraminifera and pteropods which are vitally important food for many fish.

On land, organisms that live in lakes, streams, rivers, and other bodies of freshwater are highly endangered and are especially susceptible to climate change because they cannot escape its effects, being captive in their habitat.

Most threatened are the habitats and species at high latitudes, the northern tundra and polar deserts such as those on the Arctic islands and Antarctica as well as species inhabiting high Alpine or montane habitats at middle to low latitudes.

I liked the last sentence of his chapter. In the preceding sentences he noted what he regarded as encouraging signs of acceptance of the science of global warming.  He recorded, however, still encountering individuals normally open to the discoveries of science who find it beyond belief that humans could disrupt the balance of the planet in such an enormous way. The final sentence: “But science has eventually convinced us before of the unbelievable.”

Prosperity without growth

Prosperity without Growth: Economics for a Finite Planet

I paused for a while wondering whether a review of a book on sustainable economics had a place in a website devoted to climate change. But only briefly. One can’t worry about climate change for long without considering the economies which have given rise to it and wondering how they will survive under the low-carbon regime which they must now adopt.  Anyway carbon emissions figure frequently in the course of Tim Jackson’s book Prosperity Without Growth: Economics for a Finite Planet. Published last year it was based on a report he wrote earlier in the year as Economics Commissioner of the Sustainable Development Commission, the UK Government’s independent watchdog. Increasingly climate change has imparted a new urgency to sustainability thinking. It sits as one of many issues, but it underlines the seriousness of the need to come to grips with the finitude of the planet.

The prosperity Jackson writes of is our ability to flourish as human beings. It transcends material concern. It has to do with such matters as physical and mental health, access to education, relationships and sense of community, meaningful employment and the ability to participate in the life of society. He argues that in the developed countries we can (and must) have such prosperity without the economic growth paradigm that currently rules our thinking.

Jackson recognises the difficulties of the situation we have landed ourselves with.  On the one hand growth is unsustainable, at least in its current form. The burgeoning consumption of finite resources and the heavy costs being imposed on the environment are accompanied by profound disparities in social well-being.  But on the other hand “de-growth’ is unstable, at least under present conditions. Declining consumer demand leads to rising unemployment, falling competitiveness and a spiral of recession. It adds up to a dilemma, but one which we must face and think through.

Some economists place hope in our being able to decouple economic growth from growth in physical inputs and environmental impacts.  Capitalism’s propensity for efficiency figures strongly in these scenarios. Jackson doesn’t think either the historical evidence or the basic arithmetic of growth can support the decoupling notion.  The deep emission and resource cuts needed can’t be achieved without confronting the structure of market economics.

He takes a closer look at this structure. The engine of growth is driven by the ability of the profit motive to stimulate newer, better or cheaper products and services through a continual process of innovation and ‘creative destruction’. This is matched by expanding consumer demand for these goods. A complex social logic drives this demand. Consumer goods have come to play a symbolic role in our lives.  Somehow, beyond the simple material needs they meet, they can become vehicles for our dreams and aspirations, however much they fail in delivering. The economic structure thus combines with our nature to “lock us firmly into the iron cage of consumerism”.

What we need, claims Jackson, is a new ecological macro-economics.  It will still include a strong requirement for economic stability, but it will add conditions that provide security for people’s livelihoods, ensure distributional equity, impose sustainable levels of resource throughput and protect natural capital. New variables need to be brought into play to complement and affect those already part of economic thinking. They will reflect the energy and resource dependency of the economy and the limits on carbon. They might also reflect the value of eco-system services or stocks of natural capital. Ecological investment will be important, and will mean revisiting the present concepts of profitability and productivity and harnessing them to longer term social goals. He urges the abandonment of the infatuation with increasing labour productivity in favour of high employment in low-carbon sectors.

We will need to be weaned from our dependence on consumerism, but he provides evidence that a less materialistic society will be a happier one and a more equal society a less anxious one. Greater attention to community and participation in the life of society will reduce the loneliness and unsocial behaviour which has undermined the well-being of the modern economy.

He argues that there is a clear case today for an increased role for government.  We have already seen an acceptance of this in relation to the 2008 financial crisis. The principal role of government is to ensure that long-term public goods are not undermined by short-term private interests and to deliver social and environmental goods. This role has been diminished by the need in the growth economy to support the consumerism which keeps the economy afloat.

Jackson is leery of revolution, but he proposes steps through which to build change. They fall under three main categories. First, changing the limits. Here he writes of caps on resources and emission, considers the contraction and convergence model, discusses emissions trading schemes and ecological taxes and emphasises the need for support for ecological transition in developing countries.

The second category of steps for change is fixing the economic model. The ecological macro-economics discussed above will lower expectations for labour and capital productivity and account for the value of natural capital and ecosystem services. Ecological investment in jobs, assets and infrastructure will include retrofitting buildings, advancing renewable energy technologies, redesigning networks such as the electricity grid, building public transport infrastructure, maintaining and protecting ecosystems, developing public spaces.  There will be increasing financial and fiscal prudence, including regulation of financial markets.  A Tobin tax on international currency transfers may be considered. Banks will be required to hold higher asset reserves. National accounts will be revised to be more robust than the present rough and ready GDP.

The third category is changing the social climate. Working time may be reduced. Systemic inequality will be tackled. Better measurements of prosperity will be found. Social capital will be strengthened. The culture of consumerism will be carefully dismantled.

Utopia? No, he says firmly. A financial and ecological necessity.

In a final chapter he faces the question of whether this spells the end of capitalism. Certainly growth would be slowed – labour-intense activities mean slower productivity growth, and ecological investment means a lower and longer return on capital. There would also be a larger role for the public sector in taking some ownership stake in the longer-term less productive investments. But capitalist economies often have elements of public ownership.  There is a wide spectrum of possibilities in a capitalist system.  There’s no need to polarize the debate.

I thought the book was splendid. Jackson’s writing is lucid and well organised. He has a gift for the telling sentence. (It was not altogether surprising to discover that in addition to his academic life he is a professional playwright for BBC radio.) He is cautious and sensible, not pretending that the transition to low growth is a doddle.  But he holds firmly to the conviction that it can be made and that the society which emerges will be better than the one we currently inhabit.