A recently formed group that's using veteran Washington, D.C. insiders to push for a carbon tax spent $150,000 on lobbying in the third quarter, a disclosure filing shows.

Why it matters: The amount reported on March 16 by the heavyweight firm Squire Patton Boggs on behalf of Americans for Carbon Dividends is, needless to say, quite modest by beltway standards.

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