Robert McLachlan

Robert McLachlan FRSNZ is Distinguished Professor in Applied Mathematics at Massey University and is an advocate for stronger action on climate change.

Climate explained: when Antarctica melts, will gravity changes lift up land and lower sea levels? - Climate: Explained

May 04, 2021

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change. If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz I’ve heard the gravity changes when Antarctica melts will lower the seas around New Zealand. Will that save us from sea level rise? Robert McLachlan, Massey University The gravitational changes when Antarctica melts do indeed affect sea levels all over the world — but not enough to save New Zealand from rising seas. The ice ages and their effects on sea level, geology, flora and fauna were topics of intense scientific and public interest all through the 19th century. Here’s how James Croll explained the “gravity effect” of melting ice in his 1875 book Climate and Time … Read More

Why did New Zealand’s CO2 emissions blow out so spectacularly in 2019? - Planetary Ecology

Apr 18, 2021

Every year in April, the trees start changing colour, the clocks go back an hour, and the national greenhouse gas figures are released and promptly forgotten. They take fifteen months to prepare, so by the time they come out it’s very easy for commentators to point out that they are out of date. Even now that the national media are running several new climate change stories every day, this one seems to pass us by. Not only are the figures out of date, they are also highly technical and hard to interpret: the year-to-year changes might be influenced by one-off factors like the weather, while the long-term trends have been subject to the changing winds of climate policy. The Ministry for the Environment does an amazingly thorough job of reporting greenhouse gas emissions. The latest release includes a 633 … Read More

Submit! Submit! Submit! - Planetary Ecology

Mar 25, 2021

Yes, it’s time to submit to the Climate Change Commission on their draft advice to the government, if you haven’t done so already. Submissions close on 28 March 2021.   Rod Carr / Portrait of Leo Tolstoy by Ilya Repin @NZAHParallels pic.twitter.com/enU91wnhVJ — Robert McLachlan (@nzcpe) February 28, 2021 Actually, Tolstoy can teach us a thing or two about climate change. See Michaelson 2011, Morally Differentiating Responsibility for Climate Change Mitigation: An Analogy with Tolstoy’s” Master and Man”, Business & Professional Ethics Journal, pp. 113-136, and “How Tolstoy’s War and Peace can help us understand history’s complexity“, History News Network, December 2019.   Folks – you have 7 days left to submit to the Climate Change Commission’s draft advice. Here’s a big thread with all of the template submissions … Read More

Turning and turning in the widening gyre - Planetary Ecology

Mar 24, 2021

I first wrote about New Zealand wind farms in May of 2019 (“A long time between drinks“). At that time, Mercury’s decision to build the Turitea wind farm seemed to me to be extremely significant, but also hard to interpret in terms of the larger scheme of things. Could it be that our low-emission transition was actually going to get started? By the end of that year (“Blow, winds of fruitfulness“) there had been a flurry of activity (four more wind farms?!?!?), but the future was still misty. And now here we are in March of 2021. Amidst all the excitement of the Zero Carbon Act, an election, and the Climate Change Commission getting up and running, what’s been happening with renewable energy? First, if you’re reading from overseas, a warning. This is New Zealand. You won’t be … Read More

Way to go: Electrifying advice from the Climate Change Commission - Planetary Ecology

Feb 05, 2021

The Climate Change Commission’s draft advice on how to decarbonise New Zealand’s economy is refreshing, particularly as it calls on the government to start phasing out fossil fuels instead of relying on offsets and carbon trading. Until now, New Zealand has relied heavily on its Emissions Trading Scheme, but the evidence is clear that it has failed to reduce emissions. The commission’s package includes carbon budgets out to 2035 and detailed pathways to achieve them across all sectors of the economy. For the transport sector, which is responsible for half of New Zealand’s energy-related emissions, the commission suggests a sweeping set of changes to electrify the country’s car fleet and to replace imported fuels with local renewable electricity. It’s exciting to see a national-level plan that actually cuts emissions. But it raises two questions: is it … Read More

Geyserland: Or, What happened at Taupō - Unsorted

Jan 06, 2021

I don’t know Taupō well. Even though I stop off there from time to time, I’m always on the way to somewhere else. Usually Taupō means making a hot water puddle in the gritty sand followed by a swim in the lake, noticing with bemusement and resignation the traffic, the parasailing, and the hole-in-one game. Sometimes a random, generic motel. But this time the random motel was not at all generic. Although right on the edge of town, the buildings were scattered far apart. There were typical 1970s “chalets” (i.e., DIY 4 x 2 carpentry), plus a strange assortment of structures from different periods. There was a large industrial warehouse and a deserted 500-seat bar and restaurant. (I later read that big acts like Prince Tui Teka played here in the 1970s.) Around the back there was a “historic” section, … Read More

We (still) need to talk about cars - Planetary Ecology

Dec 16, 2020

To address climate change, we need to phase out the burning of fossil fuels. The largest share of fossil fuels is burnt in cars and trucks. So it seems clear that fossil-fuelled vehicles need to stop being designed, made, imported, and driven. But anyone who has visited a road or seen a car ad recently knows that that isn’t happening, or, if it is, it’s happening so imperceptibly slowly as to hardly make a difference. In New Zealand the situation is particularly acute, as we are now very, very far down the path towards a system dominated by urban sprawl and private cars, with little regulation of either. Road transport emissions doubled between 1990 and 2018. In the US they rose 30% in the same period, and in the UK, just 6%, which campaigners still point out is woefully insufficient. Read More

Climate emergency or not, New Zealand needs to start doing its fair share of climate action - Planetary Ecology

Dec 02, 2020

Following this week’s climate emergency declaration, New Zealand will have to face up to the fact it has one of the worst climate records of industrialised nations. Of 43 industrialised countries — known as Annex 1 countries — 31 are experiencing a drop in emissions. But 12 have seen net emissions increase between 1990 and 2018, and New Zealand is near the top of this group. As part of the Paris Agreement, countries were asked to submit emissions reduction targets. These Nationally Determined Contributions (NDCs) are a measure of a nation’s commitment to contribute to the goal of limiting warming to well below 2℃. New Zealand submitted its NDC in 2015, with a headline target of bringing emissions down over the coming decade to 30% below 2005 levels. But this is not what it seems. Read More

Flight to nowhere sends the wrong message in climate crisis - Planetary Ecology

Sep 25, 2020

Qantas Airlines’ 7-hour “flight to nowhere”, that sold out in 10 minutes with prices from A$787 to A$3787, seemed like a sick joke to climate advocates. Apart from the waste of fuel and the pointless emissions, passengers would be able to see first-hand, from a plane just like those that carried coronavirus around the world so effectively, the sweeping devastation caused by last summer’s “climate fires” and the global-warming induced bleaching of the Great Barrier Reef. “Would it be more efficient just to crash it in the Great Barrier Reef?” asked Dan Rutherford, aviation director at the International Council for Clean Transportation. Now a travel enthusiast has suggested that Air New Zealand could follow suit, offering scenic flights of the entire country (not forgetting the Chathams). Actually, New Zealand does have a proud tradition of scenic flights, from small beginnings in … Read More

Are we doomed if we don’t manage to curb emissions by 2030? - Climate: Explained

Jul 29, 2020

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change. If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz Is humanity doomed? If in 2030 we have not reduced emissions in a way that means we stay under say 2℃ (I’ve frankly given up on 1.5℃), are we doomed then? Robert McLachlan, Massey University Humanity is not doomed, not now or even in a worst-case scenario in 2030. But avoiding doom — either the end or widespread collapse of civilisation — is setting a pretty low bar. We can aim much higher than that without shying away from reality. It’s right to focus on global warming of 1.5℃ and 2℃ in the first instance. The many manifestations … Read More