There was nothing too remarkable about the actual words. Plenty of others were saying the same - though not too many Liberals and fewer prominent Liberals, particularly members of the Morrison government. The following month Kean revealed that senior Liberals, including members of federal cabinet, were privately urging stronger action on climate change, and advised the federal government to drop its reliance on emission credits held over from the Kyoto agreement to meet its 2030 emissions target. That was too much for Scott Morrison.

"Matt Kean doesn't know what he's talking about," he declared. "He doesn't know what's going on in the federal cabinet and most of federal cabinet wouldn't even know who Matt Kean was."

Aimed at a fellow Liberal, it was quite a put-down. It was also a bit of a stretch, considering that Kean is leader of the Liberals' moderate, or small "l," faction in New South Wales, fancies himself as a future state premier and misses few opportunities for publicity. Any federal MPs who hadn't heard of him would have been way behind with their homework.

As for federal cabinet, bound by solidarity and secrecy, it is a sure bet that ministers are talking much more frankly to Kean than they are in public, and those most likely to be doing so are fellow moderates. Yes, they do exist in federal cabinet, including near the top of the tree - their ranks include Simon Birmingham and Marise Payne - even if their voices are muted and their influence on policy limited. This has been the lot of moderate Liberals ever since John Howard first became opposition leader in 1985.

Prominent moderate Peter Baume, a minister in the Fraser government, resigned from the Liberal Party in 1996 when Howard became prime minister because he didn't want to be associated with a conservative government. Others, like Ian Macphee, lost preselection to conservatives. Still others, like Robert Hill, environment and defence minister in the Howard government, and Christopher Pyne, a minister in every Coalition government from Howard until 2019, tried to keep the moderate flag flying by working within the government. And then there was Philip Ruddock, a critic of Howard's stance on immigration in opposition who, as immigration minister, implemented some of the harshest policies Australia has seen towards refugees.

Much of the recent public debate about the Liberals and Nationals has focused on right-wing MPs who typically oppose marriage equality and other social reforms, are climate change sceptics, if not deniers, and may doubt that COVID-19 is as serious as most people think. They have been particularly adept at leveraging their small numbers to hold the government hostage, with climate change the outstanding example. But moderates are a larger group, and some Liberals who wouldn't use that label are also increasingly frustrated at the lack of progress on urgent issues confronting the government, including climate change.

They might not be as vocal as the Craig Kellys and Barnaby Joyces, but they are showing signs of growing assertiveness. One indication is the growing support for two Liberal-aligned organisations applying pressure from outside - the Blueprint Institute and the Coalition for Conservation.

Blueprint's chief executive and co-founder, Harry Guinness, was a policy and political adviser to Julie Bishop when she was foreign minister and deputy Liberal leader. His responsibilities included foreign aid, climate change and environmental sustainability.

Last summer's bushfires were the catalyst for Guinness - self-described as "definitely philosophically a small 'l' Liberal" - and colleagues to set up Blueprint as a pro-market think tank. "With the bushfires there was a genuine sense that the time had come, after a decade of messing around with climate policy and not doing justice to what is really the biggest economic challenge of this generation and the next generation," he tells me. "It is clear there needed to be more research and a more compelling story coming from the right of politics, getting beyond the energy reliability and the affordability issues."

Guinness's first employee was Daniel D'Hotman, a Rhodes scholar he met at Oxford University, where Guinness obtained a master's degree in international development. The contrasts between Britain, which has a strong bipartisan policy on climate change, and Australia struck them both. "I was inspired by the UK," says Guinness. "It's pretty remarkable what has been achieved. Or maybe it's remarkable what has happened here. If you think of the history of conservatism and the philosophy it has, it makes sense for a conservative party to be stewards of the environment and protecting the economy and thinking ahead."

A recent Blueprint report argues that net zero emissions are inevitable by 2050 or even earlier, and the longer we delay the costlier it will be. As a first step, it says, we should commit to halving emissions from coal-fired electricity this decade.

Apart from climate change, Blueprint is conducting research and publishing papers on early learning, childcare, unemployment insurance and other social policy issues, and on economic policies including tax reform. Guinness says it has a budget of less than $1 million a year from donors who are anonymous "at this stage" but is diversifying to corporate sponsorships and membership contributions that will be made public.

Guinness has attracted a stellar cast to serve on Blueprint's Strategic Council, including two of the Liberal Party's most senior moderates, Christopher Pyne and Robert Hill. Another member is Bruce Baird, a senior minister in the NSW Greiner government who, having moved to federal parliament, was kept on the backbench by Howard. Two other former state ministers from the sensible side of the NSW Nationals, Wendy Machin and Adrian Piccoli, have also been enlisted.

Even more heavyweight is the team of "ambassadors" - Malcolm Turnbull, Lucy Turnbull, Robert Hill, Nick Greiner and Philip Ruddock - assembled by the Coalition for Conservation. Compared with Blueprint, it takes a more direct advocacy role, and also organises events, including the webinar last year that brought together Turnbull and former British prime minister David Cameron to discuss "the UK Conservative leadership on climate."

The Coalition for Conservation's chair is Cristina Talacko, whose many other roles include director of the Export Council of Australia, vice-president of the NSW Liberal Party's Women's Council, and secretary of the state party's environment and energy policy branch. She tells me that C4C, as she refers to her organisation, started five years ago under the name Conservatives for Conservation. About two years ago, it changed names because "calling ourselves conservatives was putting off a lot of the moderates or middle group." Combined with the growing momentum of the climate change debate, the decision seems to have worked: C4C has grown from about 500 signed-up supporters two years ago to 2000 last year, with numbers now standing at somewhere around 5000.

"We couldn't talk about climate change in the very early days: it was seen as a very 'left' or costly thing to discuss for Liberals," says Talacko. "The feeling was that you have to choose between the economy and the environment. We changed that perspective because we are showing that the only way to grow is to grow sustainably."

As for the vocal group in the government that opposes action to reduce emissions, she says that "you can count them on your fingers and that is a good thing." She adds that her organisation has helped to create "more of a safe space" for the voices of the centre in the party to be heard. C4C's latest webinar brings together Liberal backbenchers Katie Allen and Trent Zimmerman with advocates for electric vehicles.

Talacko has also helped lend a sense of urgency to the debate. "The Liberal Party has always been known as the party of business, and its progressive leaders are seeing these opportunities and are ready to capitalise on them. No Liberal will want to be responsible for preventing Australia from seizing the next big economic opportunity."

Recently she has advocated setting a net zero target "while it is still a choice, not an ultimatum," citing moves in Europe and the United States to impose carbon levies on international trade from countries that are dragging their heels on climate change policy. While Scott Morrison is inching towards adopting a target, he is still focusing on the costs of doing so, rather than the opportunities it creates. "Fossil fuel reliant jobs are few and at risk, while jobs in renewables are growing at a higher rate," says Talacko.

One sure sign that the debate is shifting is a recent publication by the Menzies Research Centre, the Liberal Party's official think tank. Its latest policy paper includes a lengthy introduction from executive director Nick Cater extolling the substantial contribution the farming sector can make to reducing greenhouse gas emissions. "An increase in the organic carbon content of soils of just 0.5 per cent, for example, would have the same effect as closing Australia's coal-fired power stations for three years," he writes. (Others argue that the potential is much greater and that most or all of Australia's total emissions could be offset by increasing soil carbon.)

Cater certainly isn't the first to promote the benefits of sequestering carbon in the soil. But it isn't the kind of advocacy you'd expect to hear from him. A former editor of the Weekend Australian, he continues to write a weekly column for the daily Australian in which he has revealed himself to be anything but a small "l" Liberal, let alone a climate change activist. He has railed against the "Armageddon industry," and in 2017 wrote that "time has helped illuminate the dewy-eyed naivety of the climate change policy Rudd took to the 2007 election." That policy was to sign the Kyoto accord, which Howard had refused to do, and to put a price on carbon, which happened to be Howard's policy at that election, as well as Labor's, although Cater forgot to mention that.

Cater also promoted the favourite far-right conspiracy of the time: "The science of global warming offered the intellectuals another chance to organise the world as they wanted it to be, to take charge of human affairs and to bypass the irksome process of democracy... It was an opportunity to settle old scores by refighting the lost battle of the Cold War: the fight against free markets." Strange then that Rudd's, and Howard's, plan to adopt an emissions trading scheme was based squarely on free-market economics.

If even Nick Cater has begun barracking for action on climate change, then you could say the debate really has moved on. What's next - the Nationals taking up the cause? Actually, they already have. Not Barnaby Joyce and Matt Canavan, of course, who are campaigning against a net zero target because "if the Nationals supported net zero emissions we would cease to be a party that could credibly represent farmers." Nor the Deputy Prime Minister and Nationals' leader Michael McCormack, who has to publicly support his government but thinks we should exempt agriculture if we adopt a target.

READ MORE:

Another National, NSW agriculture minister Adam Marshall, thinks that idea isn't so flash. "Ring fencing farmers from a net zero carbon target is nothing but political point-scoring based on the needs of those who think in timelines that are based on their political needs, not the future of agriculture." He wonders how farmers can help shape policy and take advantage of the opportunities it opens up if they are excluded from the target. "What I want is for farmers to be paid for the valuable environmental benefits they bring to the table for New South Wales, for biodiversity, carbon, renewables, sustainable agriculture and so many other untapped potential income streams. By cutting them out you're cutting them off."

Farmer bodies long ago left the federal Nationals in their wake. The National Farmers' Federation has a target of net zero emissions by 2050. Meat and Livestock Australia and the grain industry are aiming for net zero by 2030, and the pork industry by 2025. The National Party used to be the farmer's friend but these days you have to wonder: carving out industries may be in the interests of the coal and other fossil fuel interests that donate generously to the Nationals, but it is not in the interests of farmers.

With net zero emissions targets promised by most developed countries and every Australian state government, Liberal and Labor, with public opinion in favour of stronger action, with US President Joe Biden foreshadowing a comprehensive set of policies to tackle climate change and British Prime Minister Boris Johnson announcing a green industrial revolution, how long can the Morrison government hold back the tide?

One of the last occasions the moderates took a significant public stand was in 2006 when three backbenchers, Petro Georgiou, Russell Broadbent and Judi Moylan, crossed the floor of the House of Representatives to vote against the offshore processing of asylum seekers. When Judith Troeth threatened to do the same in the Senate, Howard withdrew the legislation rather than face defeat. It turned out to be a pyrrhic victory for the moderates, with the Gillard government enacting the same policy six years later.

Since then the moderates have been on the back foot. But the stirrings in the ranks suggest that reports of their death have been exaggerated. The big test will be the future course of national climate policy.