TORONTO — It would probably be a very different summit if Paul Martin were still in charge.

The former prime minister says Ottawa has a responsibility to put climate change high on the agenda at the G20 summit in Toronto.

In a speech in Toronto on Wednesday, Martin said the G20 is the world's new "steering committee" and can't just limit its actions to banking and economics.

Since climate change is one of the top pressing concerns for the world, Martin said the G20 needs to send signals that ensure the success of international negotiations to take place in December in Mexico.

"What is important are the signals the G20 sends to the world's negotiating tables," Martin told the Empire Club and Canadian Club in a speech that set out his definition of a successful G20 summit.

"It is crucial therefore that -- rather than a last-minute confrontation between the U.S., China and a few others as in Denmark -- that the G20 in June send out the proper signals now, so that the climate-change meeting has a chance to succeed."

Martin says the G20 also needs to confront global poverty, since it is also a huge threat to globalization.

Food security, which threatens much of Africa, has received only a slight nod from the G20 so far, notes Martin.

"The G20 must respond much more urgently than it has if it is to live up to the hopes so many have vested in it," he said.

Similarly, Martin said it's not enough to address maternal and child health through the G8.

The Harper administration has placed its maternal-health initiative solely within the G8, saying that group makes up the world's biggest donors.

But, if the initiative is to be effective, Martin said "it will have to be endorsed at the wider G20 meeting as well."

As Canada's finance minister in the 1990s, Martin was a founder of the G20 finance ministers' group, helping to start the annual meetings in the wake of the Asian financial crisis.

As prime minister, he hoped to broaden the group's agenda and elevate the meetings to the leaders' level. But that didn't happen until the financial crisis of 2008, when then-U.S. president George W. Bush realized that he needed the support of emerging markets and Europe in order to keep a lid on the global recession.

But as the host of the first meeting of the G20 as a permanent decision-making body, Prime Minister Stephen Harper has strictly limited the G20 agenda to banking regulations and economic stability.

Europe has asked him repeatedly to address climate change, in order to give momentum to flagging talks to impose limits on greenhouse gases.

And emerging markets have made it clear that they want to be part of global efforts to help developing countries, saying China and others are quickly becoming important donors and investors in Africa and elsewhere.

Canada should be using the G20 venue to show leadership in these areas, Martin said.

"The host of a summit is in a powerful position for, if it chooses, it can influence much of the agenda," he said. "We will not host another one for a generation. Let us not miss the opportunity before us."

Martin repeated comments urging the Harper government to be less obsessed with defeating a global bank tax that doesn't exist, and instead focus on getting agreement on tighter banking standards.

The "most urgent need" of the G20 in Toronto is to agree that core equity and leverage standards will be in place by early fall, Martin warned. That's because many banks and advanced countries are already forgetting the lessons of the last financial crisis.

The new standards should be mandatory and fully enforced, he added.

For now, the focus is on having a voluntary code.