Greening Without CO2? More Selective Science

In their lengthy and data-rich paper, Mishra et al. (2025) examine the notable “greening” of India’s Thar Desert from 2001 to 2023. They credit this transformation to a combination of increased monsoon rainfall and human-driven groundwater irrigation. Precipitation is said to contribute 45% to this greening, and groundwater pumping 55%​. While this allocation of credit is intriguing, what’s truly shocking is what’s not mentioned at all: CO2 fertilization.

Not once in the entire 11,000+ word document does the term “carbon dioxide,” “CO₂,” or even “fertilization” appear. This is despite the well-documented global evidence that increased atmospheric CO₂ boosts plant growth by enhancing photosynthesis and improving water-use efficiency. As Piao et al. (2019) noted in Nature Reviews Earth & Environment, “Vegetation models suggest that CO2 fertilization is the main driver of greening on the global scale”. That fact seems to have escaped the attention of this research team.

The Thar Desert, a dryland environment with historically marginal vegetation, is precisely the kind of region where CO2 fertilization effects would be most potent. Plants under water-limited conditions often respond more vigorously to elevated CO2 because they can photosynthesize more with less stomatal opening, reducing water loss. Yet somehow, in a paper that examines vegetation dynamics down to the pixel level, CO2’s role is invisible.

Graphical abstract

This omission is not an academic oversight—it is symptomatic of a broader trend in climate-related literature: selective attribution, where natural drivers that contradict apocalyptic narratives are ignored in favor of more ideologically aligned explanations like “renewable energy” and “adaptation.”

The other eyebrow-raising feature of the paper is its repeated, ritualistic invocation of renewable energy as a necessary solution for sustainability—without offering any empirical justification or economic rationale.

“Sustainable practices—efficient water management, drought-resistant crops, adaptation to rising heat stress, and renewable energy—must guide future development.”​

Must they? According to what economic model or energy systems analysis? No cost-benefit analysis is provided. No energy return on investment (EROI) data. No grid reliability assessments. No lifecycle impact comparisons. Just a declarative sentence.

Later, the authors write:

“Semi-arid and arid lands such as the Thar are ideal for capturing solar energy…highlighting the potential role of solar pumping for GW abstraction.”​

Yes, the sun shines in the desert. But this simplistic correlation completely bypasses the critical challenges: capital intensity, energy storage, intermittency, and the massive material and environmental footprint of solar installations in fragile desert ecosystems. There’s not a single mention of how renewable infrastructure will be maintained in remote, dusty, high-temperature areas notorious for degrading photovoltaic performance.

Rajasthan already sees groundwater depletion at unsustainable rates, much of it driven by energy-intensive tube well pumping. Replacing one energy source with another does nothing to fix the fundamental overuse of water. But it does serve the paper’s narrative function: renewables = good, fossil fuels = bad, evidence be damned.

The paper is a model case study in how environmental science papers often smuggle in ideological preferences under the guise of objective reporting. It tells us, for instance, that:

“Global drylands offer several options for climate mitigation, including carbon sequestration, modifying aerosol-cloud dynamics, preserving biodiversity, and enhancing renewable energy.”​

Again, there’s no quantification or evaluation of trade-offs. Solar panels will not sequester carbon. They won’t preserve biodiversity—they require clearing land. They do not modify aerosol-cloud dynamics (a pseudoscientific red herring if ever there was one). Yet these phrases roll off the page, reassuring readers that the correct moral lessons have been internalized.

Models, Monsoons, and Missing Science

The greening of the Thar Desert is a fascinating phenomenon. It is a counter-narrative to the prevailing doom-laden stories of desertification and ecological collapse. But this paper’s authors seem unwilling to follow the data where it leads. Instead, they cherry-pick their drivers (rain and pumping), ignore the most obvious one (CO2), and end with a sermon on renewables that’s completely disconnected from the empirical core of the study.

What could have been a strong observational study is instead marred by narrative conformity. In the world of environmental science today, saying “CO2 is helping” or “renewables might not be the answer” is apparently more taboo than failing to mention them at all.

For those seeking rigorous, reality-based environmental science, this paper is a cautionary tale—not a roadmap for sustainable development.

H/T Mumbles McGuirck