Those familiar with Te Radar's easygoing screen persona might be slightly startled by the forceful way in which he's holding forth in the Central Auckland cafe. Leaning forward he's so intent on making his points that his lunch threatens to congeal into an unappetising lump.
"Sorry to go on," he says at one stage, "It's just I feel so passionate about this stuff."
"This stuff" is sustainability, the subject of his TV show Global Radar.
In the series' second season, which starts this Wednesday on TV One, Te Radar travels to the US, Cuba and Peru, and around Aotearoa, talking to "people who are doing things, big and small, to create a sustainable future. Some of it's really funny, he says, "some of it's a bit sad, a lot of it's inevitably about algae - although we have spent less time in sewage treatment plants than we did in the first series."
The countries featured were chosen because they were once considered "the New World", Te Radar explains. "There was this attitude that once the resources of 'the old world' of Europe were used, there was the untapped wealth of another world to exploit.
Well, even though a lot of people still behave as though that's the case, it's no longer true, so we need to make what we've got last."
Although its title acknowledges the global nature of the issue, the show examines it from a more grassroots perspective.
"I don't tend to look at the big picture too much," Te Radar says, "because I find it hard to comprehend. Something like carbon credit trading, for example, is almost too abstract.
I'm more interested in talking to someone in Peru about the tangible topic of the biodiversity of potatoes."
Take too broad a view of environmental problems and there's the danger of becoming despondent and disempowered, he suggests.
"We spoke to Jonathan Watts, who wrote a book called When a Billion Chinese Jump in which he convincingly argues it's really the Chinese who will make the difference to global warming. China's massively polluted but I think they're at the point when they're realising they can't continue like this. Unless they address the problem, things are going to go pear-shaped and it won't matter whether you use a plastic supermarket bag or not."
But that doesn't let us off the hook here in New Zealand. "I think we should be world leaders in sustainability. Because we're a small island at the bottom of the world with a non-porous border, we have a massive advantage - we have much more control over what comes in and goes out of our country than other places.
"Look at Europe. People will buy our products if we can guarantee they're pure, traceable and environmentally friendly."
Although the innovative environmental work going on in "non-descript warehouses in places like Pukekohe and Paeroa and Mosgiel" helps reinforce his positive outlook, Te Radar does exhibit some frustration at the lack of a national vision for sustainability.
"What we need to be doing is asking, 'What's the lowest hanging fruit' and then plucking it."
If Te Radar was dictator of New Zealand - "I'd be relatively benign," he says, "but I would carry a big stick with a large figurehead of myself on it" - the first fruit to be harvested would include a programme of riparian planting around waterways and sorting out stormwater discharges and councils' effluent systems.
"It amazes me we can't do some of this stuff when we've got all this unemployment.
Look at the Kaingaroa Forest, the largest man-made forest in the world, planted by a lot of dudes in the Depression era when the government said 'We'd better give them something to do."'
Te Radar notes examples of local communities creating a resource for the future by planting fruit trees on their streets and in their parks. "And schools are doing it too. We went to one in Hamilton where the principal is really passionate. They've got this massive orchard the kids look after. Imagine the cost of buying apples or oranges for your entire school - and yet they grow theirs on trees!"
Ultimately, he says, Global Radar is an entertaining, educational and optimistic look at the future. "You know, I think humans are awesome. By focusing on people who've identified an environmental issue and are actually making a difference, the show demonstrates there's no reason we can't figure out a way to solve the hiccups we're currently facing."
Season two of Global Radar starts on Wednesday on TV One at 8pm.