Public lands as carbon sinks

When a lot of folk think about public lands and the value of these places to serve our efforts to curb global climate change they think development. They think of wind farms or solar arrays. If you think about it you can’t really blame them, that’s all they’ve had to think about – with the endless commercials put on by the big “renewable” industry (usually Big Oil patting itself on the back for diversifying), news reports, and politicians making every promise under the sun that the next shiny technology will save the day and let the public keep its wasteful habits. Unfortunately, this thinking doesn’t do a whole lot of good at reducing global warming gases – that’s because renewable energy technologies don’t replace fossil fuel power plants – thus far, they’re doing little more than to serve future increased demand for energy. It’s more cheap energy so people don’t have to think about how they use it. And the planning ! Well, these huge developments on public lands aren’t any good for wildlife either – usually they go where not a lot else has, opening that up has meant that some of the last critical habitat for many species is coveted by some of the largest economic power-houses.

When you think about public lands and the value that these places have to serve our efforts to curb global climate change I’d like you to consider a new idea that is as old as dirt ~ passive restoration. Yes, I’m suggesting that part of the answer might be to remove our footprint on those places we can – and in doing so – let the land catch it’s breath.

When everyone else is thinking of the new and shiny technology that promises to make life easy – you know, the direction that got us here in the first place – I’d ask you to consider thinking of healthy soils, vegetation communities, and bountiful wildlife – all the things you love about America’s public land. The cool thing about this is, promoting the things that you love about public lands in the West does reduce global warming gases – a lot.

Consider once again ~ the living soil…

Dirt: the least charismatic and most under-appreciated of all the diverse members of a healthy ecosystem. Earlier, I described how intact living soil crusts promote the best conditions that prevent weeds – a scourge which is right up there with global warming and livestock grazing as the most pervasive threats to biodiversity. Now I’d like you to think about that same principle – passive restoration – with regard to the soil and our atmosphere.

Forests aren’t the only ecosystems that take carbon dioxide out of the air and sink it:

Intact desert ecosystems act as carbon sinks – sequestering global warming carbon dioxide.

More so than originally thought, desert ecosystems can take carbon dioxide out of the atmosphere and fix it in the vegetation and microbiotic soil crusts (Wohlfahrt 2008). In fact, deserts and semiarid landscapes can absorb more carbon dioxide than forests and grasslands. Wohlfahrt’s recent study suggesting living soil’s healing respiration in the Mojave Desert largely corroborates the carbon sequestration potential demonstrated in other studies completed with desert shrub in Baja California and in a semiarid riparian shrubland in Arizona.

The more scientists study these dynamic relationships, the more we find that if we let it, native ecosystems on public lands have much to offer in in the way of ecological services that mitigate and sequester carbon emissions that contribute to global climate change.

Compaction of soils mitigates global warming gas sequestration potential – can actually spur emission of global warming gas

But the ecosystem services that might be used to help mitigate global climate change don’t take well to abuse. A study out of Germany assessing the fluxes of methane (warms the atmosphere at 23 times the rate of CO2) and nitrous oxide (warms at 310 times the rate of CO2 !) with forest soils found that compacted soils tend to emit nitrous oxide at up to 40 times the rate of uncompacted soils. Additionally, soils tend to absorb methane out of the atmosphere, but when compacted that same soil absorbs as little as 10% its uncompacted self and in the case of silty clay loam could even go from absorbing methane – to emitting it (Teepe et al. 2004).

It seems that when folk talk about the toll of our “ecological” or “carbon” footprint – in both cases they’re being quite literal.

These scientific revelations keep nicely in tune with what we’ve already known about the potential for planting trees – but the findings break wide open consideration for a diversity of new ideas about how we approach the “use” of public landscapes and ecosystems, including arid and semi-arid, and they ought be considered when academics, decision-makers, and I hope you, grapple with the difficult question of what to do to mitigate the consequences of climate change: Restore your public land.

Land Use and Climate Change

Of all the of reasons native ecosystems help to sequester global warming gases, I have yet to come across any indication that extractive industry and disturbing use does anything but negate that potential. And if you think about it, it makes sense. In the Mojave, it’s the smallest, most fragile members of the living community – microbiotic soil crusts – the ones most easily disturbed that draws warming gas into the soil. The vibrancy, health and diversity of ecosystems that give us clean water, clean air, and abundant wildlife are the very conditions that function efficiently and productively toward fixing carbon and other global warming gases. Unfortunately, many of our land use decisions up to this point degrade that vibrancy and simplify those systems – making them less efficient carbon sinks.

Take for example a study out of China published in the Journal of Environmental Quality. The study looked at the terrestrial carbon storage of a grassland ecosystem that was grazed versus those excluded from grazing for three years, eight years, 20, 24, and 28 years. The findings were staggering – “The aboveground net primary productivity and soil C [carbon] and N [nitrogen] storage were the highest with 24-yr GE [grazing exclusion] and the lowest with free grazing.” Grazing exclusion for two decades increased the aboveground biomass and soil carbon content by 35.7% and “could facilitate significant C [carbon] and N [nitrogen] storage on decade scales in the context of mitigating global climate change” (Wu et al. 2008).

That’s a substantial finding ! Especially when you consider that over 300 million acres of Western public lands are leased to graze livestock. Hundreds of millions of acres of public land potentially used to sink carbon – to the benefit of the wildlife that we love.

Land use studies like these rekindle many possibilities for decision-makers charged with addressing climate change. Technological innovation is only half of the picture – half of the solution. The very ideas conservationists have been advocating to promote restoration for wildlife species, ecosystems, wild places, clean water and air for decades similarly contributes to America’s potential to combat global climate change. Might land managers recognize the consequences that land uses such as grazing, logging, oil & gas and even centralized “renewable energy” developments inflict onto public lands that would otherwise mitigate climate change by sequestering carbon ? The science says they should. Could public land and wildlife managers begin to recognize carbon sequestration as a legitimate value, a legitimate “land use” to promote on public lands throughout the West ? Common sense suggests it’s the cheapest, least painful and perhaps most effective and efficient course to plot.

Yes. Land managers allow ecosystem services to play out on their own with “uses” such as the Wildland Fire Use. We can do it with global warming too. Let’s get started.

What do you think ?

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