Robert McLachlan
@robertmclachlan.bsky.social
New Zealand mathematician, writing on climate & the environment at http://planetaryecology.org
Fully electric cars overtake pure petrol in the EU in December 2025! (www.carbonbrief.org/analysis-evs...)
Already happened in NZ in December 2023!
Already happened in NZ in December 2023!
January 27, 2026 at 9:40 PM
Fully electric cars overtake pure petrol in the EU in December 2025! (www.carbonbrief.org/analysis-evs...)
Already happened in NZ in December 2023!
Already happened in NZ in December 2023!
The data at MBIE says gas reinjection at geothermal power stations really works, emissions intensity down by 2/3
January 20, 2026 at 11:24 PM
The data at MBIE says gas reinjection at geothermal power stations really works, emissions intensity down by 2/3
NZ geothermal power hit a new record on 28/12/25 – 29,367 MWh, meeting 31% of demand for the day. Looks like there will be more records set in days to come. Note a lot of capacity was offline in Nov-Dec for maintenance.
January 20, 2026 at 11:11 PM
NZ geothermal power hit a new record on 28/12/25 – 29,367 MWh, meeting 31% of demand for the day. Looks like there will be more records set in days to come. Note a lot of capacity was offline in Nov-Dec for maintenance.
I can't do the fancy graphics but in 2025 Auckland had 51 unusually hot days and only 6 unusually cold ones. The El Nino year of 1998 is starting to look normal!
Of Auckland's 10 hottest-ever days by average temperature, 4 were in 2022 and 3 were in 1998.
Of Auckland's 10 hottest-ever days by average temperature, 4 were in 2022 and 3 were in 1998.
January 14, 2026 at 11:40 PM
I can't do the fancy graphics but in 2025 Auckland had 51 unusually hot days and only 6 unusually cold ones. The El Nino year of 1998 is starting to look normal!
Of Auckland's 10 hottest-ever days by average temperature, 4 were in 2022 and 3 were in 1998.
Of Auckland's 10 hottest-ever days by average temperature, 4 were in 2022 and 3 were in 1998.
See also these charts, more here: reneweconomy.com.au/too-late-too...
January 12, 2026 at 3:12 AM
See also these charts, more here: reneweconomy.com.au/too-late-too...
See also this from 1834
January 10, 2026 at 8:20 PM
See also this from 1834
Looks like 2025 will come in close to 2021. Auckland was particularly hot in 2025, nearly a full 1 ºC above its 2000-2019 average (cf. 0.5 ºC in most other places about 0.5 ºC)
January 9, 2026 at 8:07 AM
Looks like 2025 will come in close to 2021. Auckland was particularly hot in 2025, nearly a full 1 ºC above its 2000-2019 average (cf. 0.5 ºC in most other places about 0.5 ºC)
RNZ: "international visitor arrivals in Queenstown climb 40 percent higher than pre-Covid levels", surprised me but data confirms. Nov '19 55k passengers, Nov '25 84k, up 53%.
They don't point out that this means 40%+ greater damage as well.
Unsustainable growth.
www.rnz.co.nz/news/busines...
They don't point out that this means 40%+ greater damage as well.
Unsustainable growth.
www.rnz.co.nz/news/busines...
January 8, 2026 at 10:55 PM
RNZ: "international visitor arrivals in Queenstown climb 40 percent higher than pre-Covid levels", surprised me but data confirms. Nov '19 55k passengers, Nov '25 84k, up 53%.
They don't point out that this means 40%+ greater damage as well.
Unsustainable growth.
www.rnz.co.nz/news/busines...
They don't point out that this means 40%+ greater damage as well.
Unsustainable growth.
www.rnz.co.nz/news/busines...
New Zealand too
January 8, 2026 at 6:41 PM
New Zealand too
Today is a good day for New Zealand to stop using so much oil.
January 3, 2026 at 8:19 PM
Today is a good day for New Zealand to stop using so much oil.
Although climate action is in a difficult place in New Zealand just now, there is good news if you go looking. By 2024, per-capita CO2 emissions from fossil fuels were down 31% from the peak in 2005.
January 3, 2026 at 3:37 AM
Although climate action is in a difficult place in New Zealand just now, there is good news if you go looking. By 2024, per-capita CO2 emissions from fossil fuels were down 31% from the peak in 2005.
Sepia toning reminds me of this from @slanecartoon.bsky.social
January 3, 2026 at 12:21 AM
Sepia toning reminds me of this from @slanecartoon.bsky.social
Needless to say the fuel economy target for 2025 has been missed by a wide margin and will get worse next year.
December 31, 2025 at 11:07 PM
Needless to say the fuel economy target for 2025 has been missed by a wide margin and will get worse next year.
And so 2025 ends with another disappointing month for battery EV sales in New Zealand with just 603 new light BEVs sold. Market share also down, so you can't just blame the economy.
Q3: 1,994 (6.8%) last year; 1,772 (5.0%) this year.
Q4: 2,201 (6.7%) last year; 1,802 (5.2%) this year.
Aust: 9.5%
Q3: 1,994 (6.8%) last year; 1,772 (5.0%) this year.
Q4: 2,201 (6.7%) last year; 1,802 (5.2%) this year.
Aust: 9.5%
December 31, 2025 at 11:07 PM
And so 2025 ends with another disappointing month for battery EV sales in New Zealand with just 603 new light BEVs sold. Market share also down, so you can't just blame the economy.
Q3: 1,994 (6.8%) last year; 1,772 (5.0%) this year.
Q4: 2,201 (6.7%) last year; 1,802 (5.2%) this year.
Aust: 9.5%
Q3: 1,994 (6.8%) last year; 1,772 (5.0%) this year.
Q4: 2,201 (6.7%) last year; 1,802 (5.2%) this year.
Aust: 9.5%
And this doesn't even count international aviation...
December 30, 2025 at 7:40 PM
And this doesn't even count international aviation...
Reposting this perennial favourite, "Coal Consumption Affecting Climate" from the Rodney & Otamatea Times (New Zealand) of 1912. Andrew Revkin (New York Times) brought it to wide attention in 2016. 🧵
December 29, 2025 at 8:18 PM
Reposting this perennial favourite, "Coal Consumption Affecting Climate" from the Rodney & Otamatea Times (New Zealand) of 1912. Andrew Revkin (New York Times) brought it to wide attention in 2016. 🧵
Transport emissions are difficult for sure, but some countries are making (slow) progress.
Data: robbieandrew.github.io, extracted from UNFCCC returns.
Data: robbieandrew.github.io, extracted from UNFCCC returns.
December 29, 2025 at 1:17 AM
Transport emissions are difficult for sure, but some countries are making (slow) progress.
Data: robbieandrew.github.io, extracted from UNFCCC returns.
Data: robbieandrew.github.io, extracted from UNFCCC returns.
The elephant is oil
December 28, 2025 at 6:28 AM
The elephant is oil
NZ solar power generation up 31% in 2023, 52% in 2024, 61% in 2025. Long may it continue. Still only 1.9% of total power generation to there is plenty of remaining scope.
The 4th quarter of 2025 is likely to come in at the lowest emissions and highest renewable proportion on record.
The 4th quarter of 2025 is likely to come in at the lowest emissions and highest renewable proportion on record.
December 27, 2025 at 10:33 PM
NZ solar power generation up 31% in 2023, 52% in 2024, 61% in 2025. Long may it continue. Still only 1.9% of total power generation to there is plenty of remaining scope.
The 4th quarter of 2025 is likely to come in at the lowest emissions and highest renewable proportion on record.
The 4th quarter of 2025 is likely to come in at the lowest emissions and highest renewable proportion on record.
Since this is going off, some more context on the New Zealand electricity system: 1. It's mostly renewable but it's still worth squeezing most of the fossil out of the system; solar (2%) is only just starting here so has plenty of scope; 2. less fossil = lower spot prices;
December 23, 2025 at 3:29 AM
Since this is going off, some more context on the New Zealand electricity system: 1. It's mostly renewable but it's still worth squeezing most of the fossil out of the system; solar (2%) is only just starting here so has plenty of scope; 2. less fossil = lower spot prices;
New Zealand just recorded its first-ever day of zero coal- or gas-fired electricity. In fact two days, 20 & 21 December. (Still some co-gen, about 1.8%.)
December 21, 2025 at 9:36 PM
New Zealand just recorded its first-ever day of zero coal- or gas-fired electricity. In fact two days, 20 & 21 December. (Still some co-gen, about 1.8%.)
Although the winter months are not great for solar, the third quarter saw a terrific boost, especially in utility solar (farms)
Utility solar 41.2 GWh in Q2, 62.9 in Q3 (+53%)
Distributed 128 in Q2, 148.5 in Q3 (+16%)
Total up 25% for the quarter, 64% yoy.
Next two quarters will be sensational!
Utility solar 41.2 GWh in Q2, 62.9 in Q3 (+53%)
Distributed 128 in Q2, 148.5 in Q3 (+16%)
Total up 25% for the quarter, 64% yoy.
Next two quarters will be sensational!
December 20, 2025 at 2:11 AM
Although the winter months are not great for solar, the third quarter saw a terrific boost, especially in utility solar (farms)
Utility solar 41.2 GWh in Q2, 62.9 in Q3 (+53%)
Distributed 128 in Q2, 148.5 in Q3 (+16%)
Total up 25% for the quarter, 64% yoy.
Next two quarters will be sensational!
Utility solar 41.2 GWh in Q2, 62.9 in Q3 (+53%)
Distributed 128 in Q2, 148.5 in Q3 (+16%)
Total up 25% for the quarter, 64% yoy.
Next two quarters will be sensational!