Requesting that Prime Minister Boris Johnson and Labour Leader Jeremy Corbyn to provide just a few words on the issue, host Julie Etchingham asked if the leaders "agree that climate change is the biggest issue facing the UK today?"
Both leaders failed to answer the question directly, but conceded it was a "colossal" and "massive" issue for both the UK and the wider world.
Johnson said: "I think it is a colossal issue for the entire world and the UK is meeting that challenge with the most far-reaching ambition to get to carbon neutral by 2050".
The UK was the first major economy to set a net zero emissions target for 2050 and the government has driven consistent emissions reductions over the past decade.
However, critics have argued that some other nations have more ambitious net zero targets that fall before 2050 and have also warned the UK is currently on track to miss its medium term emissions targets.
Following an hour in which he repeatedly exceeded his allotted time for answering questions and attempted to link most questions back to Brexit, Johnson also argued that leaving the EU would provide a boost to the government's net zero plans. "I know you don't want me to say this, but we need to get Brexit done in order to deliver these priorities," he said.
The comments are likely to spark criticism from green groups, which have repeatedly argued that the UK's EU membership is not a legitimate explanation for the government's failure to come forward with more ambitious climate policies.
Responding to the same question, Corbyn described climate change as "the most massive issue facing the entire world". But he faced heckling from some members of the audience as he initially focused his response on the plight of those in "the poorest countries".
"When the poorest people in the poorest countries lose out because of flooding and unusual weather patterns, when we have unusual weather patterns in this country, when we have extreme levels of air pollution, we have to have a green industrial revolution, where we invest for the future, in sustainable industries and jobs, and prevent the continuing damage to our natural world and the environment," he said.
The comments on climate change came towards the end of a debate that was widely criticised by political commentators for its failure to offer any new insights and lack of clear exchanges between the two leaders.
The debate followed a day in which environmental issues once again played a central role in the campaign with the Greens publishing their manifesto and Shadow Chancellor John McDonnell reiterating his plans to de-list companies that fail to take sufficient action on climate risks while also declining to elaborate on reports Labour could include a windfall trax on oil companies in its manifesto.
