The conventions are over, the country is pivoting toward the Nov. 8 elections, and Dave Roberts, Vox’s energy and climate blogger, is out with a post insisting, yet again, that “a carbon tax is not some magical climate cure-all.”

Roberts has said this before, many times. We (CTC) even posted a point/counterpoint with him after he poured cold water on carbon taxes in 2012, after Hurricane Sandy. Now, with so much going on — a glass ceiling-shattering nomination by the Democrats, a civil society-threatening nomination by the Republicans — should we care?

We should. For one thing, Roberts is an influential journalist; here’s NY Times superstar columnist Paul Krugman linking to Roberts last summer. For another, a carbon tax shattered its own vault of silence in the Democratic primary season; after Bernie Sanders’ unapologetic calls in speeches and the debates, advocating a tax on carbon emissions isn’t necessarily a ticket to political oblivion. Moreover, Roberts’ post today raised questions about a carbon tax’s magnitude that are worth addressing.

What set Roberts off this time was a recent editorial in Technology Review that chided the Democrats for “ignoring the one thing that could best help curb carbon emissions.” That thing is, of course, a carbon tax. The TR editorial dutifully blasted Trump’s climate denialism and the GOP’s labeling coal a “clean energy source,” and then said:

But the Democratic platform might not be meaningfully better. Although Hillary Clinton has a climate change plan, and it is supportive of President Obama’s Clean Power Plan (which is held up in the courts), and makes broad promises to cut subsidies for the oil and gas industry, it leaves out one big thing: a carbon tax. (emphasis added)

That last bit was too much for Roberts. Clinton’s energy plan, he wrote, would

• expand solar and other clean alternatives.
• increase US energy efficiency by a third and decrease US oil consumption by a third within 10 years of her taking office.
• aim to meet or exceed the carbon reduction target Obama promised in Paris: 28 percent under 2005 levels by 2025.

Roberts continued:

Clinton has said exactly how much carbon her plan would reduce. Would a carbon tax reduce more? It obviously depends! A high carbon tax would. A low carbon tax wouldn’t. A revenue-neutral carbon tax that reduces the income tax would be different from a carbon tax that funds clean energy deployment… The effects of a carbon tax depend entirely on its size and implementation details.

There’s some truth there. But let’s go further.

To begin, saying how much carbon you hope to eliminate isn’t the same as having a plan to eliminate it. And unless we’ve missed something, Clinton hasn’t spelled out how she’s going to cut oil usage by a third.

Spurred by plunging prices, U.S. consumption of petroleum products in 2015 rose for the third consecutive year and is now within 7 percent of the 2005 peak. (To see for yourself, download the latest Monthly Energy Review and navigate to Table 3.5, “Petroleum Products Supplied by Type,” totals column.) Without a stiff carbon tax that not only steers purchases away from SUVs and pickups but also counteracts the resumed trend of more miles driven, there’s no way the ambitious (on paper) Obama-Clinton fuel-economy standards can bend the petroleum curve sharply downward, as we’ve written here.

Indeed, our own modeling suggests that even a robustly rising carbon tax that reached triple digits in its tenth year would only cut oil usage from the 2005 peak by a quarter.

The chances of achieving a 28 percent cut in economy-wide CO2 emissions by 2025 are brighter, partly because 2015 emissions were already 12 percent below the year-2005 benchmark. And our model predicts that a triple-digit carbon tax would, in its tenth year, be cutting CO2 emissions by 40 percent below emissions in 2005. As the Republican candidate remarked about a different type of performance, “I guarantee you there’s no problem” — provided the tax is high enough, as our graphic shows.

But that’s with a carbon tax. Without one — or some economy-wide carbon price — it’s difficult to see how the U.S. can progress from 12% below 2005 currently, to 28% below by 2025, as we wrote in 2014, following the announcement of the historic U.S.-China emissions pact. The picture is probably little different today, insofar as the positive changes since then — coal’s accelerated demise and the rapid uptake of ever-cheaper photovoltaics — are being undermined by the rise in usage of cheap oil.

There you have it: while the Clinton energy plan may be great for solar, it doesn’t map a path to deeply cut oil use and carbon emissions. In contrast, an economy-wide carbon tax — and here Dave Roberts is right, the tax must be robust, even steep — can do both.

Did Technology Review hyperventilate when it said that without a carbon tax, the Democratic climate stance in the election “might not be meaningfully better” than the Republican? Yes, somewhat. But let’s let the Pulitzer Prize-winning fact check site Politifact have the last word.

Two months ago, Politifact fact-checked this proposition: “Bernie Sanders says only he supports carbon tax and [an] ‘aggressive’ approach to climate change.” It rated Sanders’ claim — not just that he alone among the candidates supported a carbon tax but that his climate change approach was aggressive — “mostly true.”

That’s not to say we want Clinton to call explicitly for a robust carbon tax this fall. That’s a political calculation best left to others. But let’s be clear among ourselves of her climate plan’s shortfall vis-a-vis the task at hand.

As 2016 dawns, carbon taxing has become more than just the preferred climate policy of economists. It’s taking center stage in policy discussions and climate organizing in the U.S. and around the world. The Carbon Tax Center is helping to spur that process. Here is a summary of major carbon tax developments over the past year, including the Paris climate summit and Pope Francis’s elevation of climate in his June encyclical and his September visit to the U.S.

The Paris Climate Summit Advances the Climate Cause

CTC drafted, convened, and on the eve of the Paris climate summit unveiled a “luminaries’ letter” calling on the Paris negotiators to prioritize carbon taxes, both for their own value as the most potent national-level climate policy and as a path to a harmonized global carbon price. The 32 hand-picked signatories comprise a virtual “who’s who” of leading climate economists and other “wise men” (and women) including four Nobel laureates, three former U.S. cabinet secretaries, and prominent academics from Harvard, Princeton, Stanford and the University of Chicago. The roster was bipartisan as well, topped by a Reagan secretary of state and a top Romney advisor, among others. Our outreach to the media led to extensive coverage.

Pope Francis Lends his Authority to the Carbon Tax

The pope’s June encyclical didn’t just decry climate change and call on humanity to address it, it also insisted that polluters bear the costs they impose. The encyclical engendered surprising pushback from a few prominent climate economists and journalists who misinterpreted Francis’s injunctions against carbon trading and offsets. We set the record straight — Francis is calling for polluters to pay, and he’s not interested in gimmicks that hide the price or unfairly shift the burden — and he amplified that message when he addressed Congress in September.

Public Support Grows for a Carbon Tax

CTC broke the story in April that a prominent national poll showed 2/3 support among Americans for a revenue-neutral carbon tax — a result that was buried in the data and hadn’t been reported.This and other polling in 2015 revealed that the idea of taxing carbon pollution and distributing the revenues fairly is gaining public acceptability.

British Columbia, a Carbon Tax Trendsetter

Last month we published the first report quantifying the efficacy of British Columbia’s “textbook design” carbon tax. Using official data, we concluded that BC’s carbon tax has provided the impetus for the province to reduce its emissions 3.5 times as fast as the rest of Canada, without slowing economic growth. But we noted pointedly that the recent upward creep in emissions demonstrates the limits to the province’s modest tax rate and, hence, the need to resume raising the tax rate annually. The Vancouver Sun’s report on our analysis called the BC carbon tax “a model for Americans and the world.”

New York Times Strongly (and Finally!) Endorses a Carbon Tax

The New York Times’s post-Paris editorial urged nations to “embrace carbon taxes” — the second explicit mention of carbon taxing in a Times editorial. The first mention came in June when the paper issued a rousing endorsement of carbon taxes as “one of the best policies available” to fight climate change.

Carbon Tax Legislation Gets Ready for Prime Time

Five carbon tax bills embodying that approach were introduced in the House and Senate last year — including one by presidential candidate Sen. Bernie Sanders. In our view, they constitute a quantum leap in effectiveness, transparency and fairness vis-à-vis climate legislation under discussion only half a dozen years ago. We’re fairly certain our efforts both behind the scenes and in the public sphere, including running carbon tax scenarios for Hill staff, have contributed to this marked evolution. While none of the bills have a chance of passage in 2016 in the face of GOP denialism, they are a signifier of progress and a base to build on.

Carbon Taxes Advance in the States

We’re not betting on enactment of a federal carbon tax by this Congress, but we are encouraged by grassroots activism at the state level that may provide both a policy and political template that could eventually be emulated at the national level. In particular, we’ve supported the grassroots effort underway to enact a carbon tax in Washington State, either through legislative action or a referendum in November 2016.

Out with the Old Leaders, in with the New

The electoral defeat of Canadian Premier Stephen Harper and ousting of Australian Prime Minister Tony Abbott are strong signals of public dissatisfaction with anti-climate policies. The election of Justin Trudeau as Prime Minister and Rachel Notley as premier of Alberta hold out the possibility of a national carbon tax in Canada that could serve as a model around the globe. Meanwhile, new IPCC chair Hoesung Lee has joined IMF head Christine Lagarde in strongly endorsing carbon taxes.

Cheap Oil Emerges as a Climate Villain

We worked hard in 2015 to highlight cheap oil as the “new climate villain” for engendering more driving and a reversion to gas-guzzlers — a trend that is poised to grow much worse. Unlike other commentators, we quantified this negative trend, not just in terms of CO2 emissions but, more viscerally, as equivalent to firing up nine coal-fired power plants last year alone.

President Obama Calls for Putting a Price on Carbon

In concluding his press conference at the Paris conference, President Obama argued for pricing carbon emissions in the strongest and clearest terms used by any president to date. Perhaps the question that provoked the president’s remarks was prompted by our pro-carbon tax letter released and widely reported two days earlier. Obama said: “I have long believed that the most elegant way to drive innovation and to reduce carbon emissions is to put a price on it. This is a classic market failure. If you open up an Econ101 textbook, it will say the market is very good about determining prices and allocating capital towards its most productive use — except there are certain externalities, there are certain things that the market just doesn’t count, it doesn’t price, at least not on its own.”

Looking back at last year has us excited about what’s to come in 2016. The Carbon Tax Center has been at the forefront of pursuing national carbon taxes that are proven to reduce carbon emissions. We intend to aggressively build on the positive developments of 2015 and make 2016 a banner year in the fight against climate change.

EPA Quietly Signs Off on State Carbon Taxes (Ben Geman, Frontiers of Freedom)

We Can Do Better Than Obama’s Climate Plan (US News)

EPA Power Plant Rule — Baselines Matter (Brad Plumer, Vox)

Florida G.O.P. Bigs Are Flummoxed as Climate Change Hits Home (NYT)

Progressive “Better Off Budget” Features Carbon Tax (San Diego Free Press)

CA Senate Leader Proposes Carbon Tax on Motor Fuels (Reuters)

Oil Co’s Applaud Landreiu To Chair Senate Energy (Wash Post)

EPA CO2 Regs: Costly, Bureaucratic Substitute For Carbon Tax (M. Reynolds, Huff Post)