Will 3 trillion trees solve global warming?

Rising C02 levels are helping trees and plants grow faster - and of course trees absorb C02. Photo / Alan Gibson

We are 4 times more like to be killed by an asteroid hitting the earth than being killed by a bolt of lightning. The chances of being killed by an asteroid? 1 in 20,000. I've been fascinated with outer space all my life and lately the addition of MySky to my home means I am recording National Geographic shows from all hours of the day. Did you know that the asteroid that wiped out the dinosaurs was so big that as the front end of it hit earth the back end of it was still 35,000 feet in the sky? And that the impact of this strike was so intense it exploded earth and rock back into space half way to the moon before it was pulled back down to earth.

Documentaries like this often leave you thinking about how vulnerable planet earth is... but on the other hand it shows what magnificent forces have been thrown against it over its life time. With so many comments posted on my global warming blog the other day I decided to do some more research on global warming and the results - fascinating.

A few people have told me I sit on the fence too much with global warming. I think that it's valid to not feel strongly one way or the other, especially if you're not a scientist ... but I have to say as the years tick by I'm starting to feel a bit like a kid watching his parents go through a bitter divorce. Both sides - in support or against our involvement in climate change - are sometimes bitter, personal and hysterical. From hearing lines like "millions of people will die in your lifetime" to "This is all about politicians getting into office". Not that it matters what I think, as I'm certainly no climate change expert, but I thought I would give you my official line...and at the risk of sounding very Peter Dunne bland I am a strong believer of the "common sense approach". Yes, I think we are seeing some parts of the world experiencing more extremes. Yes, I think we, as humans, need to work harder to be more respectful to the environment and plan for cleaner, renewable ways of living. And yes, I think it's vital that we plan for a worse case scenario. However I am firmly of the attitude that the hysteria surrounding the global warming debate is utterly mad.

Who's to blame for the hype? Well it's easy to blame the media - and so I'm not going to. The media is simply the vehicle that both sides of the argument use to voice their opinions. Both sides have their activists and unfortunately it's the typical minority that feed the emotion and hype into this topic. Many of you responded the other day by saying you felt that there wasn't an independent voice out there. I think they are out there, but they're bombarded by more extreme people on either side.

Do I think mankind has polluted the planet? Yes, definitely - it's obvious. Do I think mankind has added to global warming? Without a doubt. Do I see it as being a catastrophic problem. No. Not catastrophic. Am I qualified to have an opinion? Probably not on an official document...but it's often those who aren't caught up in the debate that are most likely to see the wood for the trees.

And lets say 3 trillion trees. NewstalkZB morning host and well known climate change sceptic Leighton Smith forwarded me a fascinating article from the New York Times last week. We can solve global warming instantly - simply plant 3 trillion trees. This is a suggestion from a highly respected (perhaps until recently) physicist in America, Freeman Dyson. The 85 year old has stunned many around him by "coming out of the closet as far global warming is concerned" as he sometimes puts it.

Al Gore's dramatic, and perhaps a bit over the top, scene where he rides a cherry picker up a large screen to indicate just how much CO2 has risen over the past century highlighted something positive to Dyson. He says C02 is good for the earth - it's fertiliser for the entire planet. Helping trees and plants grow faster - and of course trees absorb C02.

Dyson is a problem solver. He loves looking at the challenges we face as human beings and he loves to find ways to solve them. He says not only should we be planting 3 trillion trees but scientists should be working hard to create a "super tree" that absorbs more CO2 than any other tree on the planet. As this article above says, Dyson is a great problem solver who believes climate change isn't a great problem.

The scientist was widely respected before his view on climate change hit the news. Now people who respected him before are saying his brain is simply "too old". However top doctors confirm his brain is still as magnificent as ever. Dyson sounds intelligent and doesn't say mankind hasn't contributed - just that it's not as big a deal as some are making it out to be. He also hated Al Gores movie and goes through it to set a few things straight.

The article also raises another interesting point - those who challenge the facts surrounding global warming are often criticised for being "evil".

I decided to talk to someone at NIWA for their thoughts on Dyson's theory - and also to get a better understanding as to how much politics play a part in global warming findings.

Dr David Wratt is NIWA's Chief Scientist for Climate. He's a pleasant man who was cautious about getting caught up in another global warming debate. As you saw in my last blog about global warming this is a heated topic and those from both sides of the fence argue about who is right and who is wrong. Dr Wratt corrected me very early in the interview when I asked about NIWA obviously supporting the global warming theory. He cut me off before I had time to ask my question in full to ask me "What do you mean by 'theory'?". This lead to the main thrust of my conversation with him and he makes a good point. "It's not about beliefs it about evidence...evidence, evidence, evidence".

During our 30 minute phone interview he pointed out in great detail that it's all about evidence, facts and multiple groups of scientists looking at the same data and coming up with the same conclusions. Scientists don't just "support things" - they need evidence. "Not just 1 scientist or 1 group - but several groups coming to the same conclusion".

I have to say from personal experience I know this is true. I'm not a scientist but I've watched them debate weather models and weather data and to the every day person it is actually quite mind boggling how detailed these people get. You can't help but get a feeling of assurance when listening to this...they get excited by minute details.

"Look at the evidence. There's very clear evidence that the world has warmed over the last 100 years. In the past the climate has changed due to the sun, the earths orbit, volcanoes etc". Dr Wratt went on to say that over the past 100 years it's clear that those things are not responsible for the increase in greenhouse gases in the past 50 years, mankind is.

I brought up the New York Times interview with Freeman Dyson. "The climate system is pretty complex. You need proper analysis. You need to do a whole of different things - there's no silver bullet". Dr Wratt suggested planting 3 trillion trees would give us a "breathing space" but that ultimately we need to lower emissions. Trees also don't remove C02 - they only remove it from the atmosphere. Of particular concern is the Brazilian rainforest. If climate change causes trees to die or rain to stop falling across certain large forests then even more C02 will be released into the atmosphere. As oceans warm up they also release C02.

I suggested to Dr Wratt that in the past single people, like Darwin for example, have proven that the majority isn't always right. He agreed there is a history of scientists coming up with a whole new paradigm of the world. In terms of climate change Dr Wratt believes there's just so much strong scientific evidence they are confident they are on the right page. "I'm not arguing that we know absolutely everything. It's only by questioning things that you improve".

Bob McDavitt, from MetService, has an experiment you can try. It's the coke bottle theory. "To give the experiment some extra credence explain that it is a variation of one of the experiments at earth.uni.edu " he said in an email to me. Bob says that CO2 is a trace gas - but a strong one at that. In his words "Like chilli in curry". Click the link to read about it.

Conclusion:

As I said in my previous global warming blog, I'm not a scientist. I think there are alarmists on both sides of the fence. The sceptics often say it's "all about politics" and those that believe we need to act now say that sceptics are "bought off" by large companies.

I really am the Peter Dunne of global warming (shudder) - I believe in a common sense approach. Of course my opinion means nothing but I do believe that we as humans definitely need to keep the planet clean. If this debate is becoming political is that really such a bad thing? Is it such a bad thing that America finally embraces being clean and green? That our dependence on things like coal and oil may perhaps ease in the near future? That an estimated billion people switched off their lights recently in support of making our planet cleaner? Even if you're a global warming sceptic you have to agree that a cleaner and greener earth is a good thing.

From talking to NIWA - and I understand that NIWA aren't the worldwide voice on global warming - but after talking to Dr Wratt you can't help but get the feeling they know what they're talking about and that the alarmist language used in public debates doesn't come from them.

I strongly suggest you read that New York Times article. Dyson makes some fantastic points and the more you read about him the more you can't help but take him seriously. Again, it adds weight to my theory that the majority are probably right but that people like Dyson remind us it doesn't have to be the biggest challenge we face this century.

Leighton Smith is a sceptic, as was the late Augie Auer. I always enjoyed listening to Leighton's interviews with Augie on this topic. While I don't always agree with the sceptics I can't say I always agree with people like Al Gore either. I like to hear both sides of the story. I think most of the detailed data is so confusing to everyday folk that we have to rely on our scientific community. Perhaps a TV debate involving scientific sceptics and those at NIWA would be a good idea? I'm sure many New Zealanders would benefit from that - a chance to hear both sides and a chance for actual scientists, not just angry people who don't understand the facts, to debate the climate change evidence. It's easy when you don't understand all the facts to build up an opinion based on someone else's ideology.

- Philip Duncan