Tackling the climate crisis is so much more than bean counting.

In the March issue, I lamented how many major decisions are framed in ‘narrow boundary’ terms when we desperately need ‘wide-boundary’ thinking. I didn’t mention trees, carbon forests, etc., so let’s explore how they fit.

Let’s start with climate basics. Most human carbon dioxide emissions come from fossil fuels. They’re the biggest source of global warming and will keep overheating our planet for centuries. (It’s those centuries that make slashing methane crucial because methane’s heating impact does drop quickly.)

A key challenge is removing CO₂ from the air far faster than we add to it by rapidly cranking down CO₂ emissions and cranking up sucking them from the air.

Despite the hoo-ha about engineered “carbon capture and storage” systems, they offer no realistic prospect of rapid, large-scale effectiveness. Which makes plants the heroes, sequestering CO₂ from the air and storing it for varying lengths of time. And trees are superheroes, with half their mass being carbon from the air and stored for as long as they aren’t rotting or burning.

At last year’s Agriculture and Climate conference, Rod Carr, outgoing Climate Change Commission chair, didn’t mince his words: “If we don’t stop the use of fossil fuels, we’re toast. We must phase them out, not just phase them down.”

Got it.

And removing CO₂? “Trees are problematic,” Carr highlighted, “because they are not permanent, but CO₂ emissions, in essence, are.”

There’s the rub. For the validity of carbon forests for offsetting CO₂, they must store carbon indefinitely. But forests are vulnerable—and climate change makes droughts, storms, fires, etc., even worse. So how might carbon forests work when they need to store carbon reliably for—well, forever?

The Parliamentary Commissioner for the Environment took a close look and cautioned that the Crown (i.e., us) may be liable if carbon forests become compromised.

The PCE’s first two recommendations included phasing out forestry offsets for fossil emissions and allowing (shorter-lived) biogenic methane to be offset by forestry.

The Science Media Centre had specialists review the PCE’s report. They widely agreed, but some went further. “Kill carbon forestry,” wrote one, while another noted, “Carbon farming is essentially treating the climate emergency as just another opportunity to make money while ignoring future financial and environmental liabilities.”

Let’s take an even wider boundary view (wider than ‘forever’? Yeah, right!).

Since the last Ice Age, humans have cleared a third of the world’s forests, in essence, launching man-made climate change 10,000 years ago. The Amazon Rainforest is now so depleted that it’s releasing carbon instead of sequestering it, and New Zealand has deforested a whopping 60% in just 1000 years.

An even wider boundary? Climate is just one dimension of ‘overshoot,’ with numerous ‘planetary boundaries’ now crossed, with biodiversity loss becoming an even bigger concern than climate change. (And Pinus radiata forests suck for biodiversity.)

The bottom line: plant indigenous trees like there’s no tomorrow. (“If not trees, then what?” was Carr’s challenge.)

Plus, slash fossil fuels ASAP (or faster).

Plus, never ever kid ourselves that planting trees magically makes it okay to keep burning fossil fuels.

If we do, we’re toast.