For better or worse, Trudeau's next 4 years are going to be about climate change

So who is Justin Trudeau now?

He is unlikely to emerge from the result of the October 21 election as a wholly different person. He's surely still the same complicated figure he was before this fall's campaign. He is also still the prime minister.

But things have changed. His government's situation, his public standing and the demands upon himare different now. And the aftermath of an election offers a natural pivot point, a chance to take stock of what's been and adjust for what's to come.

When last we heard from the prime minister at any length (nearly a month ago),he was talking about taking some time to "reflect."

He has not yet reported back with the fruits of that reflection. In fact, his public appearances have been relatively limited since election night.

There was no rah-rah speech to supporters the day after the election, as there was in 2015. There was no Halloween photo-op appearance in costume withhis kids. In 2015, he gave himself just 16 days to set up a new government. This time, he has taken nearly a month.

"You are sending our Liberal team back to work," Trudeau told the country after the election result became clear. And when we've seenTrudeau since then, we've seen him at work in his West Block office, wearing a suit and tie, meeting with a succession of party leaders and premiers, speaking briefly in constructive and conciliatory terms before taking the discussions behind closed doors.

Which is not to say he has acted entirely likea shrinking violet.

After Saskatchewan Premier Scott Moe emerged from his meeting with Trudeau and blasted the prime minister for apparently not immediately agreeing to move on Moe's latest demands, Trudeau's office responded with an unusually long "readout" of the discussion that responded in detail to Moe's concerns and openly challenged the premier to broker an equalization agreement with the other provinces.

But even this flourish was based in the fussy details of public policy.

Perhaps what we've seen from Trudeau over the past four weeks is areflection of thereflecting he promised to do.

No margin for error

Between October's narrow election result and the lingering memories of the blackface photo scandal that nearly killed his re-election chances,Trudeau seems to have less liberty now to appear anything less than substantive and serious at all times. For the PM, rebuilding his political fortunes would seem to depend more on what he does than on what he says.

His first opportunities to show real change come in the days ahead, as he names a new cabinet and settles on the structure of his office.

Opinions vary on the performance of Trudeau's team over the first four years of his government. While it nimbly managed the seismic challenge of Donald Trump and NAFTA's renegotiation, on other matters (the India trip, the SNC-Lavalin affair) the first term Trudeau government regularly found new and inventive ways to get itself in troubletrouble that ultimately made it much harder to get re-elected.

And assessing an organization always ought to start at the top.

In the wake of SNC-Lavalin, Trudeau started to adjust his own approach by reaching out to Liberal MPs to improve his relationship with thecaucus, for example. But some kind of shake-up in his office became inevitable when Gerry Butts, Trudeau's close friend and most influential adviser, resignedas principal secretary.

Butts returned for the campaign but he will not be back in the PMO. A Trudeau PMO without Gerry Buttswill be different. It remains to be seenhow different.

Katie Telford will return as chief of staff. But the status of the rest of the staff positions including Butts' old job hasn't been announced. However it shakes out, officialOttawa will be watching to see how (or if) Trudeau's government functionsdifferently.

First, he needs a cabinet.After weeks of mostly futile speculation, that big reveal happens Wednesday.

The new cabinet lineup will be quickly praised or panned by the media according to whose political stock seems to be up, whose is down and whether Trudeau demonstrates the discipline to make changes without significantly increasing the size of cabinet.

But Trudeau's choices might be more important for what they say about how he intends to confront the treacherous new territory before him: a restless West and a Parliament that will now have to be managed with greater care.

For dealing with Parliament, Trudeau will need a solid House leader. For the West, there is no simple answernot least because he cannot draw on a single MP from Alberta or Saskatchewan and his most senior MP in Manitoba, Jim Carr,iscoping with cancer.

Part of the answer might lie in the names Trudeauchooses for the environment and natural resources portfolios. It might also involve someone in cabinet beingassigned an economic development or intergovernmental affairsportfolio with an emphasis on the western provinces(possibly a job for Alberta-bornChrystiaFreeland).

Trudeau's party technically only lost a handful of seats on the Prairies but the Liberalshutout in Alberta and Saskatchewan, and the intensity of the Conservative vote, are freighted with heavy political symbolism Trudeau can't ignore.

The results in those two provinces also seem to underline what has emerged as the core issue of Trudeau's time in office. The first four years of Trudeau's government touched on a broad swath of issues, from economic equality to Indigenous reconciliation, populism and diversity.

But the issue that cameto the fore during this fall's election campaign was climate change, along with the transition to a low-carbon future and all that entails. This is the defining issue in federal politics now; nearly everything the government does now is affected by it in some way.

Though his party's own share of the vote was reduced, Trudeau has latched on to the fact that nearly two-thirds of voters castballots for candidates whose parties promised a price on carbon and a concertedeffort to cutgreenhouse gas emissions.

Climate change remains the major policy fault line between Liberals and Conservatives,and it offers Trudeau a path forward as he tries to maintain support for his government in the House of Commons. It is also, underneath all the sound and fury, the most significant point of tension between Ottawa and the West.

The Trudeau government was the first federal government to make meaningful progress toward reducing Canada's carbon emissions and the Liberals became just the second government in Canada after Gordon Campbell's provincial Liberal government in B.C. in 2009 to be re-elected while promising a tax on carbon emissions.

Trudeau's reward is a chance to keep pushing the transition, with all the tension and pressure that entails.

However he chooses to move forward, whoever he decides to surround himself with, he is likely to be defined by his success or failure in the pursuit of a low-carbon future.