But that amount — which tallies the group's initial formal lobbying since its formation — is slated to increase along with other aspects of the much wider, 7-figure advocacy push, according to Ted Halstead, the group's CEO.

• “As our financial support grows, all facets of the campaign will expand,” he tells Axios.
• The campaign also includes paid media, coalition-building, grassroots efforts and more, Halstead says.

Background: Americans for Carbon Dividends is the recently formed advocacy offshoot of the Climate Leadership Council, whose leaders include James Baker and other GOP senior statesmen.

The big picture: The groups are pushing a plan that includes...

• Installing a rising CO2 tax that begins at $40-per-ton.
• Returning the proceeds to the public.
• Phasing out EPA's regulatory powers.
• Shielding fossil fuel companies from tort claims over their emissions.

ICYMI: Americans for Carbon Dividends, backed by interests including the nuclear power operator Exelon and renewables companies, made headlines this month when ExxonMobil pledged $1 million over 2 years.

• The group has raised $3.4 million so far for 2 years of work and that amount is slated to grow, Halstead recently told my colleague Amy Harder.

What's next: My eyes are peeled for the Q3 filing from the Alliance for Market Solutions Action, another group pushing for conservatives to embrace a revenue-neutral carbon tax married to repeal of regulations.

• They spent nearly $41,000 on lobbying in Q2, which was their first since formally registering to lobby.

But, but, but: These filings don't capture all the lobbying action around CO2 taxes. For instance, Shell, which backs CO2 pricing, also lists the topic in its own reports.

• But they're a useful reminder that when it comes to efforts to win conservative buy-in, there's a long, long way to go and the money behind the effort is still a drop in the beltway bucket.

Go deeper:

• Nuclear, renewable firms fund new group pushing carbon tax
• Exxon gives million-dollar backing to carbon tax push