Boreal forest on the edge of a climate-change tipping point

15 11 2016

As some know, I dabble a bit in the carbon affairs of the boreal zone, and so when writer Christine Ottery interviewed me about the topic, I felt compelled to reproduce her article here (originally published on EnergyDesk).

A view of the Waswanipi-Broadback Forest in the Abitibi region of Northern Quebec, one of the last remaining intact Boreal Forests in the province (source: EnergyDesk).

A view of the Waswanipi-Broadback forest in the Abitibi region of northern Quebec, one of the last remaining intact boreal forests in the Canadian province (source: EnergyDesk).

The boreal forest encircles the Earth around and just below the Arctic Circle like a big carbon-storing hug. It can mostly be found covering large swathes of Russia, Canada and Alaska, and some Scandinavian countries.

In fact, the boreal – sometimes called by its Russian name ‘taiga’ or ‘Great Northern Forest’ – is perhaps the biggest terrestrial carbon store in the world.

So it’s important to protect in a world where we’re aiming for 1.5 or – at worst – under two degrees celsius of global warming.

“Our capacity to limit average global warming to less than 2 degrees is already highly improbable, so every possible mechanism to reduce emissions must be employed as early as possible. Maintaining and recovering our forests is part of that solution,” Professor Corey Bradshaw, a leading researcher into boreal forests based at the University of Adelaide, told Energydesk.

It’s not that tropical rainforests aren’t important, but recent research led by Bradshaw published in Global and Planetary Change shows that that there is more carbon held in the boreal forests than previously realised.

But there’s a problem. Read the rest of this entry »





Ice Age? No. Abrupt warmings and hunting together polished off Holarctic megafauna

24 07 2015
Oh shit oh shit oh shit ...

Oh shit oh shit oh shit …

Did ice ages cause the Pleistocene megafauna to go extinct? Contrary to popular opinion, no, they didn’t. But climate change did have something to do with them, only it was global warming events instead.

Just out today in Science, our long-time-coming (9 years in total if you count the time from the original idea to today) paper ‘Abrupt warmings drove Late Pleistocene Holarctic megafaunal turnover‘ demonstrates for the first time that abrupt warming periods over the last 60,000 years were at least partially responsible for the collapse of the megafauna in Eurasia and North America.

You might recall that I’ve been a bit sceptical of claims that climate changes had much to do with megafauna extinctions during the Late Pleistocene and early Holocene, mainly because of the overwhelming evidence that humans had a big part to play in their demise (surprise, surprise). What I’ve rejected though isn’t so much that climate had nothing to do with the extinctions; rather, I took issue with claims that climate change was the dominant driver. I’ve also had problems with blanket claims that it was ‘always this’ or ‘always that’, when the complexity of biogeography and community dynamics means that it was most assuredly more complicated than most people think.

I’m happy to say that our latest paper indeed demonstrates the complexity of megafauna extinctions, and that it took a heap of fairly complex datasets and analyses to demonstrate. Not only were the data varied – the combination of scientists involved was just as eclectic, with ancient DNA specialists, palaeo-climatologists and ecological modellers (including yours truly) assembled to make sense of the complicated story that the data ultimately revealed. Read the rest of this entry »





Earth’s second lung has emphysema

19 02 2015
© WWF

© WWF

Many consider forests as the ‘lungs’ of the planet – the idea that trees and other plants take up carbon and produce oxygen (the carbon and oxygen cycles). If we are to be fair though, the oceans store about 93% of the Earth’s carbon pool (excluding the lithosphere and fossil fuels) and oceanic phytoplankton produces between 50 and 80% of the oxygen in the atmosphere. For comparison, the terrestrial biosphere – including forests – stores only about 5% of the Earth’s carbon, and produces most of the remainder of atmospheric oxygen.

So there’s no denying that the biggest player in these cycles is the ocean, but that’s not the topic of today’s post. Instead, I’m going to focus on the terrestrial biosphere, and in particular, the carbon storage and flux of forests.

Now it’s pretty well established that tropical forests are major players in the terrestrial carbon cycle, with the most accepted estimates of about 55% the terrestrial carbon stock stored therein. The extensive boreal forest, covering most of the northern half of North America, most of Scandinavia and a huge chunk of Russia, comes in globally at about 33%, and temperate forests store most of the remainder.

That is, until now. Read the rest of this entry »





When human society breaks down, wildlife suffers

22 01 2015

bearGlobal human society is a massive, consumptive beast that on average degrades its life-support system. As we’ve recently reported, this will only continue to get worse in the decades to centuries to come. Some have argued that as long as we can develop our societies enough, the impact of this massive demographic force can be lessened – a concept described by the environmental Kuznets curve. However, there is little evidence that negative societal impact on the environment is lessened as per capita wealth exceeds some threshold; unfortunately environmental damage tends to, on average, increase as a nation’s net wealth increases. That’s not to say that short-term improvements cannot be achieved through technological innovation – in fact, they will be essential to offset the inexorable growth of the global human population.

So poor nations as well as the wealthy ones are responsible for environmental damage. Poorer nations often have ineffective governance systems so they fail to enforce compliance in environmental regulations, but wealthier nations often exploit a high proportion of their natural resources, with the inevitable environmental damage this entails. In some cases however, biodiversity can temporarily escape some of the ravages of society because humans either perceive the area to be too dangerous, or otherwise have no incentive to go there. There are some good examples of the latter, such as the vicinity around the Chernobyl nuclear reactor that melted down in 1986, or the Korean demilitarised zone.

In this vein, I just stumbled across an extremely interesting paper today published online early in Conservation Biology that describes trends in charismatic wildlife (i.e., big mammals) as the former Soviet Union collapsed in 1991 and societal breakdown ensued. The authors had access to an amazing dataset that spanned the decade prior to the collapse, the decade immediately following, and a subsequent decade of societal renewal. What they found was fascinating. Read the rest of this entry »





Eye on the taiga

24 03 2014

boreal damageDun! Dun, dun, dun! Dun, dun, dun! Dun, dun, daaaaah!

I’ve waited nearly two years to do that, with possibly our best title yet for a peer-reviewed paper: Eye on the taiga: removing global policy impediments to safeguard the boreal forest (recently published online in Conservation Letters).

Of course, the paper has nothing to do with cheesy Eighties music, underdog boxers or even tigers, but it does highlight an important oversight in world carbon politics. The boreal forest (also known as taiga from the Russian) spans much of the land mass of the Northern Hemisphere and represents approximately one quarter of the entire planet’s forests. As a result, this massive forest contains more than 35% of all terrestrially bound carbon (below and above ground). One doesn’t require much more information to come to the conclusion that this massive second lung of the planet (considering the Amazon the first lung) is a vital component of the world’s carbon cycle, and temperate biodiversity.

The boreal forest has been largely expanding since the retreat of the glaciers following the Last Glacial Maximum about 20,000 years ago, which means that its slow progression northward has produced a net carbon sink (i.e., it takes up more atmospheric carbon that it releases from decomposition). However, recent evidence suggests that due to a combination of increased deforestation, fire from both human encroachment and climate change, mass outbreaks of tree-killing insects and permafrost melting, the boreal forest is tipping towards becoming a net carbon source (i.e., emitting more carbon into the atmosphere than it takes up from photosynthesis). This is not a good thing for the world’s carbon cycle, because it means yet another positive feedback that will exacerbate the rapid warming of the planet. Read the rest of this entry »





Get boreal

7 06 2012

I’ve been a little quiet this last week because I’ve had to travel to the other side of the planet for what turned out to be a very interesting and scientifically lucrative workshop. After travelling 31 hours from Adelaide to Umeå in northern Sweden, I wondered to myself if it was going to be worth it for a 2.5-day workshop on a little island (Norrbyskär) in the Baltic Sea (which, as it turned out, didn’t have internet access).

The answer is a categorical ‘yes’!

Many of you know that I’ve dabbled in boreal forest conservation in the past, but I could never claim any real expertise in the area. Hence it came as something of a shock when Jon Moen of Umeå University asked me to attend a specialist workshop focused loosely on making the plight and importance of the boreal forest more widely acknowledged. I dragged my feet initially, but Jon convinced me that I could add something to the mix.

It was a small workshop, but well-represented by all boreal countries save Norway (i.e., we had Russians, Swedes, Finns, Canadians and Americans – this Australian was indeed the odd one out). We also had a wide array of expertise, from carbon accountants, political scientists, political economists, native cultures experts, ecologists to foresters. Our mandate – justify why we should pay more attention to this globally important region.

Just how important is the boreal forest? We managed to unearth some little-appreciated facts: Read the rest of this entry »





Who are the world’s biggest environmental reprobates?

5 05 2010

Everyone is a at least a little competitive, and when it comes to international relations, there could be no higher incentive for trying to do better than your neighbours than a bit of nationalism (just think of the Olympics).

We rank the world’s countries for pretty much everything, relative wealth, health, governance quality and even happiness. There are also many, many different types of ‘environmental’ indices ranking countries. Some attempt to get at that nebulous concept of ‘sustainability’, some incorporate human health indices, and other are just plain black box (see Böhringer et al. 2007 for a review).

With that in mind, we have just published a robust (i.e., to missing data, choices for thresholds, etc.), readily quantifiable (data available for most countries) and objective (no arbitrary weighting systems) index of a country’s relative environmental impact that focuses ONLY on environment (i.e., not human health or economic indicators) – something no other metric does. We also looked at indices relative to opportunity – that is, looking at how much each country has degraded relative to what it had to start with.

We used the following metrics to create a combined environmental impact rank: natural forest loss, habitat conversion, fisheries and other marine captures, fertiliser use, water pollution, carbon emissions from land-use change and threatened species.

The paper, entitled Evaluating the relative environmental impact of countries was just published in the open-access journal PLoS One with my colleagues Navjot Sodhi of the National University of Singapore (NUS) and Xingli Giam, formerly of NUS but now at Princeton University in the USA.

So who were the worst? Relative to resource availability (i.e,. how much forest area, coastline, water, arable land, species, etc. each country has), the proportional environmental impact ranked (from worst) the following ten countries:

  1. Singapore
  2. Korea
  3. Qatar
  4. Kuwait
  5. Japan
  6. Thailand
  7. Bahrain
  8. Malaysia
  9. Philippines
  10. Netherlands

When considering just the absolute impact (i.e., not controlling for resource availability), the worst ten were:

  1. Brazil
  2. USA
  3. China
  4. Indonesia
  5. Japan
  6. Mexico
  7. India
  8. Russia
  9. Australia
  10. Peru

Interestingly (and quite unexpectedly), the authors’ home countries (Singapore, Australia, USA) were in either the worst ten proportional or absolute ranks. Embarrassing, really (for a full list of all countries, see supporting information). Read the rest of this entry »





Global rates of forest loss – everyone’s a bastard

29 04 2010

© A. Hesse

I’ve written rather a lot about rates of forest loss around the world, including accumulated estimates of tropical forest loss and increasing fragmentation/loss in the boreal forest (see Bradshaw et al. 2009 Front Ecol Evol & Bradshaw et al. 2009 Trends Ecol Evol). For the tropics in particular, we used the index that an area of rain forest about the size of Bangladesh (> 15 million hectares) was disappearing each year, and in Russia alone, annual decline in forest area averaged 1.1 million hectares between 1988 and 1993. Mind boggling, really.

But some of these estimates were a bit old, relied on some imprecise satellite data, and didn’t differentiate forest types well. In addition, many have questioned whether the rates are continuing and which countries are being naughty or nice with respect to forest conservation.

It was great therefore when I came across a new paper in PNAS by Hansen & colleagues entitled Quantification of global gross forest cover loss because it answered many of the latter questions.

Part of the problem in assessing worldwide forest cover loss in the past was the expense of satellite imagery, access problems, data storage and processing issues. Happily, new satellite streams and easing of access has rectified many of these limitations. Hansen & colleagues took advantage of data from the MODIS sensor to create a stratification for forest cover loss. They then used the Landsat ETM+ sensor as the primary data for quantifying gross forest cover loss for the entire planet from 2000 to 2005. They defined ‘forest cover’ as “… 25% or greater canopy closure at the Landsat pixel scale (30-m × 30-m spatial resolution) for trees > 5 m in height”.

For your reading pleasure (and conservation horror), the salient features were: Read the rest of this entry »





Fragmen borealis: degradation of the world’s last great forest

12 08 2009
© energyportal.eu

© energyportal.eu

I have the dubious pleasure today of introducing a recently published paper of ours that was at the same time both intellectually stimulating and demoralising to write. I will make no apologies for becoming emotionally involved in the scientific issues about which my colleagues and I write (as long as I can maintain with absolute sincerity that the data used and conclusions drawn are as objectively presented as I am capable), and this paper probably epitomises that stance more than most I’ve written during my career.

The topic is especially important to me because of its subtle, yet potentially disastrous consequences for biodiversity and climate change. It’s also a personal issue because it’s happening in a place I used to (many, many years ago) call home.

Despite comprising about a third of the world’s entire forested area and harbouring some of the lowest human densities anywhere, the great boreal forest that stretches across Alaska, Canada, Scandinavia and a huge chunk of Russia is under severe threat.

Surprised that we’re not talking about tropical deforestation for once? Surprised that so-called ‘developed’ nations are pilfering the last great carbon sink and biodiversity haven left on the planet? If you have read any of the posts on this blog, you probably shouldn’t be.

The paper today appeared online in Trends in Ecology and Evolution and is entitled Urgent preservation of boreal carbon stocks and biodiversity (by CJA Bradshaw, IG Warkentin & NS Sodhi). It’s essentially a review of the status of the boreal forest from a biodiversity perspective, and includes a detailed assessment of the degree of its fragmentation, species threat, climate- and human-influenced disturbance regime, and its carbon sequestration/emission status. I’ll summarise some of the main findings below:

borealfire

© NASA

  • Russia contains ~53 % of the boreal forest, followed by Canada (25 %), USA (18 %, mostly in Alaska), Sweden (2 %) and Finland and Norway (~1 % each); there are small areas of boreal forest in northern China and Mongolia.
  • Fire is the main driver of change in the boreal forest. Although clearing for logging and mining abounds, it pales in comparison to the massive driver that is fire.
  • There is evidence that climate change is increasing the frequency and possibly extent of fires in the boreal zone. That said, most fires are started by humans, and this is particularly the case in the largest expanse in Russia (in Russia alone, 7.5 and 14.5 million hectares burnt in 2002 and 2003, respectively).
  • While few countries report an overall change in boreal forest extent, the degree of fragmentation and ‘quality’ is declining – only about 40 % of the total forested area is considered ‘intact’ (defined here as areas ≥ 500 km2, internally undivided by things such as roads, and with linear dimensions ≥ 10 km).
  • Russian boreal forest is the most degraded and least ‘intact’, and has suffered the greatest decline in the last few decades compared to other boreal countries.
  • Boreal countries have only < 10 % of their forests protected from wood exploitation, except Sweden where it’s about 20 %.
  • There are over 20000 species described in the boreal forest – a number much less than that estimated for tropical forests even of much smaller size.
  • 94 % of the 348 IUCN Red Listed boreal species are considered to be threatened with extinction, but other estimates from local assessments compiled together in 2000 (the United Nations’ Temperate and Boreal Forest Resources Assessment) place the percentages of threatened species up to 46 % for some taxa in some countries (e.g., mosses in Sweden). The latter assessment placed the Fennoscandian countries as having the highest proportions of at-risk taxa (ferns, mosses, lichens, vascular plants, butterflies, birds, mammals and ‘other vertebrates’), with Sweden having the highest proportion in almost all categories.
  • Boreal forest ecosystems contain about 30 % of the terrestrial carbon stored on Earth (~ 550 Gigatonnes).
  • © BC Ministry For Range/L. Maclaughlan

    Warmer temperatures have predisposed coniferous forest in western Canada to a severe outbreak of mountain pine beetle (Dendroctonus ponderosae) extending over > 13 M ha. © BC Ministry For Range/L. Maclaughlan

  • Mass insect outbreaks killing millions of trees across the entire boreal region are on the rise.
  • Although considered in the past as a global carbon sink, recent disturbances (e.g., increasing fire and insect outbreak) and refinements of measurement mean that much of the area is probably a carbon source (at least, temporarily).
  • A single insect outbreak in western Canada earlier this decade thought to be the direct result of a warming planet contributed more carbon to the atmosphere than all of that country’s transport industry and fire-caused release combined.
  • Current timber harvest management is inadequately prepared to emulate natural fire regimes and account for shifting fire patterns with climate change.
  • No amount of timber management can offset the damage done by increasing fire – we must manage fire better to have any chance of saving the boreal forest as a carbon sink and biodiversity haven.

Those include the main take-home messages. I invite you to read the paper in full and contact us (the authors) if you have any questions.

CJA Bradshaw

Full reference: Bradshaw, CJA, IG Warkentin, NS Sodhi. 2009. Urgent preservation of boreal carbon stocks and biodiversity. Trends in Ecology and Evolution DOI: 10.1016/j.tree.2009.03.019

Add to FacebookAdd to NewsvineAdd to DiggAdd to Del.icio.usAdd to StumbleuponAdd to RedditAdd to BlinklistAdd to Ma.gnoliaAdd to TechnoratiAdd to Furl








%d bloggers like this: