This morning I spoke with Diego Saez Gil, the co-founder and CEO of Pachama — a Y Combinator graduate bringing machine learning to the tricky business of reforestation. In short, Pachama ensures that when a company says it’s offsetting emissions by planting trees, the planting actually gets done.

“We use remote sensing, including satellite images and Lidar data, to monitor and verify the claims of the forest carbon projects,” Saez Gil says, adding the platform wants to bring greater transparency to the carbon offset market — which trades increasingly in trees.

Just last week, the World Economic Forum strong-armed leaders into supporting its 1 trillion trees initiative — a platform that hopes to unite the world’s various reforestation campaigns, including the similar-sounding Trillion Trees Initiative, which aims to plant a trillion trees.

Critics have warned the PR push on forests distracts from the greater and more difficult challenge of actually reducing carbon emissions and I’m inclined to agree. Tree growth is also a tediously slow process, so the promised offsets won’t happen until well into the future and could even then be negated by a wildfire, drought or some other disaster. But there’s another issue.

“Today there’s more demand than certified supply for tree planting as a carbon offset,” Saez Gil says. That doesn’t mean there isn’t enough potential land to host one trillion trees. According to researchers at ETH Zurich, there’s 0.9 billion hectares of land worldwide that’s viable for reforestation, which could home 1.2 trillion trees and store 205 billion tonnes of carbon.

The problem, Saez Gil says, is in the certification process, which assesses how much carbon a proposed reforestation project would capture. The current process, which relies a lot on manual checks, takes years. Pachama is trying to speed the system up.

“We train deep learning algorithms using Lidar data — collected from flyovers using drones or an airplane — field plots — which is data collected on the ground by forest services — and also satellite images. The algorithms start to learn that a certain combination of colors, shapes and tree species contain a certain amount of carbon and, eventually, we can start making predictions of carbon absorption rates,” Saez Gil says.

Once Pachama has certified a plot of land, it can be sold on the carbon market and then the plot’s growth can be tracked through the start-up’s user dashboard. So if a tree falls, someone knows about it.

Microsoft, which last week pledged to turn carbon negative by 2030, has partnered with Pachama to achieve that goal and if Pachama’s system reaches scalability it could help hundreds others conscientiously plant trees. But Saez Gil gladly admits that reforestation is “not a silver bullet.”

“We need to reduce emissions and move away from fossil fuels. We can’t keep business as usual just because we keep planting trees,” says Saez Gil.

***

Another carbon sequestration start-up that caught my eye this week is Texas born Hypergiant Industries, which is experimenting with algae blooms as a means to remove CO2 from the environment. According to CEO Ben Lamm, the company’s Eos Bioreactor — an AI-monitored, fridge-sized unit that houses an algae sludge — is 400 times more efficient in carbon uptake than trees.

The product, which is in beta at the moment, attaches to the exhaust pipe of an industry’s heating, ventilation and air conditioning (HVAC) system, where the algae can feed on the CO2.

“We are running up against a ticking clock and unfortunately trees do not grow fast enough to rapidly reduce the growing atmospheric carbon levels…In the context of carbon sequestration and combating climate change, there are more powerful and faster alternatives that should be prioritized,” Lamm says.

***

Eamon Barrett
Eamon.Barrett@Fortune.com

CARBON COPY

The usual

Two climate researchers say that the “business as usual” case for global warming often cited by scientists and media is actually an increasingly unlikely worst-case scenario. The projection in question, RCP8.5, represents a carbon emissions pathway leading to global temperature rise of 5°C, but the author say real “business as usual” would lead to an average rise closer to 3°C. Lest this error be seized by climate change deniers, however, the authors point out it doesn’t make climate action less urgent. “The need to limit warming to 1.5°C…does not depend on having a 5°C counterpoint. Nature

The tax man

The Trump Administration threatened to “react” against the EU’s proposed carbon tax, with Commerce Secretary Wilbur Ross warning the carbon tax could be “in its essence protectionist.” Ross likened the proposed tax to plans from various EU countries to impose a “digital service tax,” that impacts companies like Google and Facebook. The White House has opposed that tax, too. Financial Times

Gender and growth

The International Union for the Conservation of Nature has reported a link between climate change and increased violence against women. As climate change puts increased stress on resources, that scarcity creates situations where women are either exploited or vulnerable to attack. Cate Owren, one of the report authors, says, “Gender-based violence is one of the most pervasive but least talked-about barriers that face us in conservation and climate work.” The Guardian

IN CASE YOU MISSED IT

Running on EV: The race to solve lithium-ion battery recycling before it’s too late by Tamara Warren

The 2020 candidates’ positions—and records—on economic issues that affect women by Emma Hinchliffe

Recycling hasn’t changed in years, but America is on the cusp of a reckoning by Tracey Lindeman

Fortune poll: Investors want corporations to focus on more than just shareholders by Lance Lambert 

Why microgrids are key to solving energy poverty worldwide by Rajiv J Shah and Natarajan Chandrasekaran

How businesses can see big changes coming ahead of time by Rita McGrath

CLOSING NUMBER

56%

Climate change is coming for your cabernet. According to researchers at the University of Alcalá, Spain, an average global temperature rise of 2°C would make 56% of global wine country unsuitable for viticulture. A rise of 4°C would cut back the vineyard by 85%. The study was limited — for example, it only considered 11 of the more than 1,000 grape varieties available —  and there’s other reasons not to panic: wine makers could adapt by diversifying their vineyards with different grapes, while warming temperatures would open up new regions to greater wine growing.