The European Union has joined with Canada and China to convene a ministerial summit in Montreal this weekend, in preparation for the United Nations climate summit taking place in November in Bonn, Germany.

Though ministers from 30 major economies will be present, accounting for half of the G20, one major economy will not have a senior minister there - the United States. That is as intended.

The summit is, in part, an effort to head off any attempts by the US to play a spoiler role at the Bonn talks.

US President Donald Trump announced his intent to withdraw his country from the Paris climate agreement in June. But since then it has become clear that the US is in no hurry to pull out, and will still have a seat at the table until 2020. That has left other signatories to the deal worried that US representatives will use their delegation to thwart efforts to strengthen the regime at this year's summit in Bonn.

The Montreal meeting is the first of its kind, because it has been called by individual countries and is taking place outside the UN framework.

EU Climate Commissioner Miguel Arias Cañete is leading discussions at the Montreal summit

Before leaving for the ministerial meeting, Miguel Arias Cañete, the EU's climate commissioner, said that the Paris agreement remains strong even in light of the US renunciation. "The EU remains committed to the Paris Agreement and its full and swift implementation," he said. "Internationally, we are strengthening our existing partnerships and seeking new alliances. Our aim is to raise global climate ambition, follow through with concrete action and support our partners, in particular the most vulnerable countries."

European Commission President Jean-Claude Juncker had harsh words for Trump's decision in his State of the European Union address earlier this week. "I want Europe to be the leader when it comes to the fight against climate change," he said. "Set against the collapse of ambition in the United States, Europe will ensure we make our planet great again. It is the shared heritage of all of humanity."

Canadian Prime Minister Justin Trudeau will open the meeting today and host a roundtable discussion with Cañete.

The US will not be completely unrepresented. Everett Eissenstat, deputy director of the US National Economic Council, will be present. However, he is not expected to take the floor.

Ministers will also discuss other climate issues not related to the Paris Agreement, such as emissions limits for shipping and aviation, and emissions trading.

Recent hurricanes may be softening President Trump's stance on climate change

Thawing climate stance in America?

The EU has not given up on the United States entirely. Following the Montreal summit, Cañete will fly to New York to attend a meeting on Monday morning with Trump advisor Gary Cohn, director of the National Economic Council.

Recent media reports have given EU leaders some hope that Trump's climate stance may be softening, particularly following the unprecedented season of hurricanes currently wreaking havoc in the Southern US. This week US media reports said Trump may be considering replacing Obama's climate legislation, enacted to get the US to its Paris emission reduction commitment, rather than repealing it entirely.

Energy companies are concerned that a full repeal will open the administration up to lawsuits and result in years of uncertainty, according to reports.