A Step Toward Honest Climate Science

Returning Integrity to National Climate Science

Independent scientists have long criticized the U.S. Fifth National Climate Assessment (NCA5) for treating extreme emission pathways—RCP8.5 and SSP5-8.5—as realistic baselines.

These scenarios were designed as upper-bound tools for modeling, not as likely futures, and they conflict with observed trends in energy use and technology.

In August, the Trump administration proposed an amendment to NCA5 requiring that results based on these pathways no longer serve as expected, business-as-usual, or policy-relevant projections. Figures and claims relying on them must now carry clear caveats and be compared with more plausible alternatives and real-world data.

This is a constructive step that curbs inflated risk estimates and the costly regulations they supported. Broader issues remain, however. Climate models have often overestimated warming, while the assessment downplays the benefits of rising CO₂.

At about 420 parts per million, CO₂ enhances photosynthesis, improves water efficiency of plants, and raises crop yields. Satellite data show global greening largely driven by this effect, and fossil-fuel-based fertilizers help feed roughly half the world’s population. Modest warming has also extended growing seasons and reduced cold-related deaths in many regions.

Aggressive net-zero measures that restrict reliable energy create higher costs, slower development, and greater food insecurity. Sound science starts with observations, tests models rigorously, and weighs both risks and benefits. The amendment offers useful progress; policymakers should now review the full assessment against data and restore balance by acknowledging CO₂’s positive role.

The CO₂ Coalition has spent years advancing precisely this evidence-driven approach, documenting the life-enhancing role of carbon dioxide, exposing overstated scenarios, and pressing for policies grounded in observation rather than alarm. Supporting our work helps ensure that science continues to guide decisions that deliver energy abundance, a healthier Earth, and genuine human flourishing.

Chart of the Week

The National Oceanic and Atmospheric Administration (NOAA) recently announced that July 2026 was the warmest month on record for the contiguous U.S. This claim was based on temperature measurements made from their more than 10,000 observation stations. Unfortunately, this data is not pristine, and the more recent temperatures are artificially warmed by the “Urban Heat Island” effect (UHI).

U.S. Historical Climatology Network (USHCN) consists of 1,218 stations and is a subset of stations that NOAA has selected that lessen UHI biases and other artificial factors influencing the data.

Was last July the hottest on record in the U.S.? We accessed the USHCN data on August 26 and plotted the average July temperature beginning in 1895 and found that four previous years recorded higher average July temperatures than last month, including in 1901, 1934, and 1936 at a time when carbon dioxide levels were less than 75% of current concentrations.

The Latest from CO₂ Coalition Staff and Members:

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EU Decarbonization Is a Security Threat for the West - CO2 Coalition

From Vijay Jayaraj:

End of ‘Green’ Enslavement in Latin America - CO2 Coalition

CO₂Coalition Weekly Substack from Ron Stein:

California is Running Out of Refineries – And Running Out of Time

Our Latest Climate Debrief Podcast Episode:

CO₂ in Perspective with Dr Byron Soepyan Part 2| Climate Debrief

Please join the CO₂ Coalition in Our Legal Fight

to Repeal the Endangerment Finding

On March 20th, the CO₂ Coalition filed a motion to intervene in the legal battle over the EPA’s repeal of the so-called Endangerment Finding. This critical action responds directly to environmental organizations and several states that have challenged the EPA’s February decision.

The EPA correctly determined that it lacks authority under the Clean Air Act to regulate carbon dioxide as a pollutant.

We are taking aggressive legal action to defend sound science and protect American families from the economically destructive policies driven by climate alarmism. This fight is central to our mission: restoring scientific integrity and preventing government overreach that harms jobs, energy prices, and economic freedom.

However, mounting this legal defense has created a significant budget deficit. Legal interventions of this importance are expensive, and we cannot sustain this effort without your support.

Your contribution today will directly help us push back against these regulatory attacks and defend the repeal of the Endangerment Finding.

Please join us in this vital battle. Every donation makes a difference in our ability to fight — and win — for science, freedom, and prosperity.

Thank you for standing with the CO₂ Coalition!

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