09/22/2014 12:17 EDT | Updated 11/22/2014 05:59 EST

Climate change just one of many 'significant challenges' for Canada: Harper

UNITED NATIONS, N.Y. - Prime Minister Stephen Harper says climate change is just one item on a long list of "significant challenges" Canada will be wrestling with in New York this week.

Harper will spend several days here, participating in a question-and-answer session with business leaders, speaking at the United Nations General Assembly and joining UN Secretary-General Ban Ki-moon at an event on women's health.

However, it will be Canada's environment minister, Leona Aglukkaq, who attends Tuesday's UN climate-change summit on behalf of the government.

When asked why he wasn't attending himself, Harper suggested it's because he already has a lot on his plate.

"Every year, when we go to New York this particular week — and obviously part of it which we we spend at the United Nations — we're seized with any number of significant challenges that are before us," he told a news conference Monday on Parliament Hill.

"If we look at this year, we have new and emerging peace and security threats that range from the form of terrorist organizations to major countries, in the case of the threat against Ukraine; we have challenges of development, humanitarian aid, pandemics; we have challenges of human rights and governance; we have trade issues and the economy; and obviously, I try and touch on a number of these, including climate change."

The Canadian government, however, is being confronted with an issue it might rather avoid.

The $860-million Rockefeller brothers charitable fund, created from a family oil fortune, has announced it will dump its fossil-fuel investments. That brings to an estimated $50 billion the total amount institutional investors around the world have pledged to withdraw from fossil fuels over the next five years.

Harper will attend a working dinner Tuesday on climate change, where his office said in a statement he'll discuss Canada's efforts to reduce greenhouse gas emissions, adapt to a changing climate, invest in research and work with other countries on climate change, "while still encouraging economic growth and job creation."

"Canada will be very well represented at the climate change summit," Harper said.

"I look forward to tomorrow evening with president Park and many other leaders in the important discussions we will have, hosted by the secretary general of the United Nations, on how we can work together collectively on how we can address this particular issue."