How Well Have Climate Predictions Done?

Batten, Don.  “Climate Change:  A biblical and scientific approach to Anthropogenic Global Warming.”  Creation Ministries International.  Feb 17, 2026 (edition of 2020).  CMI's main statement on modern climate, a long essay by its scientist Don Batten, a former research horticulturalist with the New South Wales Department of Agriculture, written with colleagues.  It sets out a biblical history of climate, a critique of the climate movement, a scientific case for low climate sensitivity and against the temperature records, and a policy section.  This article tests every factual claim in it. ↩

1. 1a.

   Section The fruit:  “The Arctic sea ice area measured each September (the end of summer, its lowest extent of the year) declined from about 7.5 million km₂ in 1980 to about 4–5.5 million km₂ from 2010–2020 (NSIDC/NASA)”. ↩

2. 1b.

   Section Predicting the future temperature is difficult:  “The UN’s IPCC stated in 2001 that: “The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible.””  “Nevertheless, that is exactly what they did, predict the future temperature! But because it is so complex, over 100 different models have been used—if it were clear cut (simple), or ‘settled’ there would be one model.” ↩

3. 1c.

   Section Sea levels (tidal data):  “According to satellite measurements, sea levels are now rising at about 3.3 mm/year”.  “However, there is little evidence of any acceleration in the sea level rise”. ↩

4. 1d.

   Section Sea levels (tidal data):  “Fort Denison in Sydney Harbour shows perhaps a 100 mm (4 in) rise in sea level in 100 years”. ↩

5. 1e.

   Section Sea levels (tidal data):  “They found that the global pumping of groundwater from 1993–2010 had contributed over 6 mm rise in sea level.” ↩

6. 1f.

   Section Sea levels (tidal data):  “If all the Antarctic ice melted, this would cause a rise in sea level of some 57.2 m (190 ft). This would of course be disastrous to many people globally. However, how long would this take to happen, based on the estimated rates of melting from the most recent period, 2009–2017?”  “82,000 years!” ↩

7. 1g.

   Section The fruit:  “In 1989 the UN said, “Entire nations will be wiped out by the year 2000 if sea level rises are not stopped.” Did this happen? No!” ↩

8. 1h.

   Section The fruit:  “Anyone who remembers the 1970s will recall that we were all going to freeze in another ice age. Of course, ‘we’ could do nothing about that, so some of the same ‘experts’ who were running with that switched to ‘global warming’ and then, when the temperature data did not match the models that gave the dire predictions, it morphed into ‘climate change’.” ↩

9. 1i.

   Section Predicting the future temperature is difficult:  “Nearly all the models seriously over-predict global surface temperature response to rising CO2—see Figure 2.”  “The models are simply wrong.” ↩

10. 1j.

    Section Coral reefs:  “In a “personal perspective” written by Dr Nancy Knowlton, Sant Chair for Marine Science at the Smithsonian’s National Museum of Natural History, and published in 2012, 90% of the living coral in the central and southern sections would be gone “in just 10 years”.”  “Not even close!” ↩

11. 1k.

    Section Coral reefs:  “A study of the long-term bleaching of the GBR, from drill cores, showed periods of severe bleaching going back to the 1700s, well before any recent ‘global warming’.” ↩

12. 1l.

    Section The fruit:  “Since 2005, the global polar bear population has increased.” ↩

13. 1m.

    Section The fruit:  “They were most definitely not ‘unprecedented’ in terms of either lives lost or area burnt. For example, in the 1938–39 fire season, over 80 lives were lost in bushfires in Victoria and NSW, compared to 34 in the recent fires. And the 5 million hectares burnt compares with 117 million hectares in the fires of 1974–75.” ↩

14. 1n.

    Section Extreme weather events:  “However, the historical data don’t bear out these claims.”  “Note that a related paper published in 2022 in Eur. Phys. J. Plus 137 was withdrawn by the publisher in a very non-transparent process after political pressure was brought to bear by a gang that included notorious ‘Climategate’ participants.” ↩

15. 1o.

    Section Sea levels (tidal data):  “Indeed, this has been found to be an area of sub-glacial volcanic activity, as it sits over the West Antarctic Rift System that includes 138 known volcanoes.”  “That is, the melting could occur even if all anthropogenic CO2 production stopped tomorrow.” ↩

16. 1p.

    Section Sea levels (tidal data):  “The authors claimed that if this one glacier melted, global sea level would rise by an impressive 1.5 m (5 ft).”  “However, a recent re-estimation of the ice volume of all 215,000 glaciers outside of Antarctica and Greenland concluded that if they all melted, sea levels would rise “up to 30 cm” (one foot).”  “This does not seem to tally with the Denman glacier claim. Indeed, we calculated that the contribution of the Denman glacier would be no more than about 6 mm (¼ in)!” ↩

17. 1q.

    Section Concern for the environment:  “Indeed, the increase in CO2 is now responsible for 30% of the world’s biomass production (food and fibre) over the last century, as documented in a paper in Nature in 2017.”  “Deserts are greening, largely because of the extra CO2.” ↩ ↩

18. 1r.

    Section Ocean acidification:  “There is evidence from in situ experiments with coral communities that they can acclimatize to much higher CO2 levels.” ↩

19. 1s.

    Section The fruit:  “However, Tuvalu has increased 3% in land area over the last 40 years.”  “A survey published in 2018 of 30 Pacific and Indian Ocean atolls, including 709 islands, revealed that no atoll had lost land area in recent decades.” ↩

20. 1t.

    Section The fruit:  “In 2007, Dr Tim Flannery, an evolutionary mammologist who headed up the Australian government’s climate change unit, predicted that even the rain that would fall would not be enough to fill the reservoirs. Australia has had major floods since then.” ↩

Hausfather, Zeke et al.  “Evaluating the performance of past climate model projections.”  Geophysical Research Letters 47:e2019GL085378.  2020.  A check of seventeen model projections of global temperature published from 1970 to 2007 against the warming that followed, scored two ways:  temperature against time as published, and warming per unit of the forcing that actually occurred.

1. 2a.

   Section Results:  “Using the temperature versus time metric, 10 of the 17 model projections show results consistent with observations.”  “Using the implied TCR metric, 14 of the 17 model projections were consistent with observations”. ↩

2. 2b.

   Page 7:  “H88's “most plausible” Scenario B overestimated warming experienced subsequent to publication by around 54%”.  “However, much of this mismatch was due to overestimating future external forcing—particularly from CH4 and halocarbons”. ↩

3. 2c.

   Section Discussion, page 8:  “H88 A and B forcings increased 97% and 27% faster, respectively, than the mean observational estimate, and FAR forcings increased 55% faster.”  “On an implied TCR basis, all three projections have high model skill scores and are consistent with observations.” ↩

Hausfather, Zeke et al.  “Climate simulations:  recognize the 'hot model' problem.”  Nature 605:26–29.  2022.  A comment by five climate modellers and researchers warning that a subset of the newest generation of models warm too much for a given rise in CO2, and urging users to weight models by how well they match other evidence, as the IPCC's 2021 report did.

1. 3a.

   Page 26:  “Users beware: a subset of the newest generation of models are ‘too hot’”.  “and project climate warming in response to carbon dioxide emissions that might be larger than that supported by other evidence”.  Page 28:  “In CMIP6, more than one-quarter of models have sensitivities that are greater than this”.  “Numerous studies have found that these high-sensitivity models do a poor job of reproducing historical temperatures over time”.  The superscript reference numbers in the original are left out.  "This" is the 4.7 °C maximum of the previous model generation. ↩

Spencer, Roy W., and John R. Christy.  “Effective climate sensitivity distributions from a 1D model of global ocean and land temperature trends, 1970–2021.”  Theoretical and Applied Climatology 155:299–308.  2023.  A peer-reviewed estimate by the two UAH climatologists, fitting a simple heat-flow model of land and ocean to measured surface, deep-ocean and borehole warming trends for 1970–2021 under two forcing histories.  It finds sensitivity near the low end of the IPCC range and below 34 of 36 current models.

1. 4a.

   Section 1, Introduction:  “Finally, we note that the global average surface warming since 1970 — the 50 + year period with the largest anthropogenic radiative forcing of the climate system — has been weaker in observations than in 80% of 36 CMIP6 climate models”. ↩

McKitrick, Ross, and John Christy.  “Pervasive Warming Bias in CMIP6 Tropospheric Layers.”  Earth and Space Science 7:e2020EA001281.  2020.  A statistical comparison by an economist and the UAH climatologist of temperature trends in 38 of the latest climate models with balloon, satellite and reanalysis records of the lower and middle troposphere, globally and in the tropics, for 1979–2014.

1. 5a.

   Section Abstract:  “all 38 models overpredict warming in every target observational analog, in most cases significantly so”. ↩

Santer, Benjamin D. et al.  “Causes of differences in model and satellite tropospheric warming rates.”  Nature Geoscience 10:478–485.  2017.  A mainstream study, with Remote Sensing Systems' satellite team among its authors, of why the satellite record of the troposphere warmed more slowly than models after 2000.  It attributes the gap partly to errors in the forcings given to the models and finds natural variability alone an unlikely explanation.

1. 6a.

   Section Abstract:  “model tropospheric warming is substantially larger than observed”.  The full sentence begins "Over most of the early 21st century, however," and continues "warming rate differences are generally outside the range of trends arising from internal variability."  The abstract concludes that the overestimate "is partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations." ↩

Least-squares trends on the monthly global anomalies of UAH v6.1 ⁴⁴ and RSS v4.0 ⁴⁶, in °C per decade:  1979–2025, UAH 0.156 and RSS 0.231;  1988–2006, UAH 0.169 and RSS 0.273.  UAH annual means average −0.28 °C for 1979–1988 and +0.33 °C for 2016–2025.  For the tropical middle troposphere ⁴⁵⁴⁷, 1979–2025:  UAH 0.113 and RSS 0.157. ↩

Hausfather, Zeke, and Glen P. Peters.  “Emissions – the 'business as usual' story is misleading.”  Nature 577:618–620.  2020.  A comment by two mainstream energy and climate researchers arguing that the IPCC's highest emissions scenario, RCP8.5, had been wrongly treated as the expected future, and that current policies point to about 3 °C of warming by 2100.

1. 8a.

   Page 618:  “RCP8.5 was intended to explore an unlikely high-risk future”.  Page 619:  “Emission pathways to get to RCP8.5 generally require an unprecedented fivefold increase in coal use by the end of the century”.  “Assessment of current policies suggests that the world is on course for around 3 °C of warming above pre-industrial levels by the end of the century”. ↩

Intergovernmental Panel on Climate Change.  Climate Change 2001:  The Scientific Basis.  Cambridge University Press.  Edited by J. T. Houghton, Y. Ding, D. J. Griggs, M. Noguer, P. J. van der Linden, X. Dai, K. Maskell and C. A. Johnson.  2001.  The IPCC's third assessment of the physical science, the report CMI cites for the CO2 forcing formulas and for its sentence on the chaotic climate system.

1. 9a.

   Chapter 14, Executive Summary, page 771:  “The climate system is a coupled non-linear chaotic system, and therefore the long-term prediction of future climate states is not possible. Rather the focus must be upon the prediction of the probability distribution of the system’s future possible states by the generation of ensembles of model solutions.”  Section 14.2.2.2, page 774:  “The most we can expect to achieve is the prediction of the probability distribution of the system’s future possible states by the generation of ensembles of model solutions.” ↩

2. 9b.

   Section Foreword:  “The Intergovernmental Panel on Climate Change (IPCC) was jointly established by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) in 1988.” ↩

NASA Goddard Space Flight Center.  Global Mean Sea Level Trend from Integrated Multi-Mission Ocean Altimeters TOPEX/Poseidon, Jason-1, OSTM/Jason-2 and Jason-3, version 5.1.  2021.  NASA's merged satellite-altimeter record of global mean sea level, every ten days from late 1992, here to August 2024.

1. 10a.

   Column 9, sea level with glacial isostatic adjustment applied:  −37.90 mm at the start of 1993, +69.84 mm in August 2024;  least-squares slope 3.30 mm a year over 1,164 values. ↩

Nerem, R. Steven et al.  “Climate-change–driven accelerated sea-level rise detected in the altimeter era.”  Proceedings of the National Academy of Sciences 115(9):2022–2025.  2018.  An analysis of 25 years of satellite altimetry that removes the effects of the 1991 Pinatubo eruption and of El Niño before fitting a curve, to see whether sea-level rise is speeding up.  It finds a small but significant acceleration.

1. 11a.

   Page 2022:  “we estimate the climate-change–driven acceleration of global mean sea level over the last 25 y to be 0.084 ± 0.025 mm/y2.” ↩

Frederikse, Thomas et al.  “The causes of sea-level rise since 1900.”  Nature 584:393–397.  2020.  A budget of global sea-level rise since 1900 that adds up melting glaciers and ice sheets, ocean warming and changes in water stored on land, including groundwater pumping and dams, and checks the total against tide gauges and satellites.

1. 12a.

   Page 393:  “The acceleration in sea-level rise since the 1970s is caused by the combination of thermal expansion of the ocean and increased ice-mass loss from Greenland.”  Page 394:  “Our GMSL estimate (Fig. 1a) shows a trend of 1.56 ± 0.33 mm yr−1 (90% confidence interval) over 1900–2018.” ↩

Hamlington, Benjamin D. et al.  “The rate of global sea level rise doubled during the past three decades.”  Communications Earth & Environment 5:601.  2024.  A short paper by NASA's sea-level team updating the altimeter record to the end of 2023 and fitting its rate and acceleration, with stated uncertainties.

1. 13a.

   Section Abstract:  “since satellites began observing sea surface heights in 1993 until the end of 2023, global mean sea level has risen by 111 mm.”  “the rate of global mean sea level rise over those three decades has increased from ~2.1 mm/year in 1993 to ~4.5 mm/year in 2023.”  Section Introduction:  “The average rate of GMSL rise over the full length of the altimeter record - currently 3.3 mm/year - has been a widely-used metric for tracking the changes occurring to our climate system”.  “however, is increasingly misleading.”  The paper gives the acceleration as 0.08 ± 0.06 mm a year per year, with every ± a 90 % interval. ↩ ↩

Least-squares slopes of the Fort Denison 2 annual means ⁴⁸, leaving out the three years flagged as missing:  1.17 mm a year for 1915–2024 and 3.75 mm a year for 1993–2024.  The tide gauge measures sea level against the land, so these are local, not global, rates. ↩

Smith, Ben et al.  “Pervasive ice sheet mass loss reflects competing ocean and atmosphere processes.”  Science 368(6496):1239–1242.  2020.  A comparison of NASA's laser-altimeter satellites ICESat (2003–2009) and ICESat-2 (2018–2019) measuring how the height, and so the mass, of the Greenland and Antarctic ice sheets changed over sixteen years.

1. 15a.

   Page 1239:  “Losses outpaced gains, with grounded-ice loss from Greenland (200 billion tonnes per year) and Antarctica (118 billion tonnes per year) contributing 14 millimeters to sea level.” ↩

Rignot's paper gives Antarctica's yearly snowfall as 2,100 Gt and equal to 5.8 mm of sea level, so 1 mm is about 362 Gt ¹⁷.  At 252 Gt a year the loss is 0.70 mm a year, and 57,200 mm takes about 82,000 years.  At the 1979–1990 rate of 40 Gt a year it would take about 520,000 years.  Both are constant-rate illustrations, not projections. ↩

Rignot, Eric et al.  “Four decades of Antarctic Ice Sheet mass balance from 1979–2017.”  Proceedings of the National Academy of Sciences 116(4):1095–1103.  2019.  A reconstruction of how much ice Antarctica gained and lost each year from 1979 to 2017, from satellite measurements of ice flow in 176 drainage basins compared with modelled snowfall.  It is the source of CMI's 14 mm and 57.2 m figures. ↩

1. 17a.

   Page 1095:  “The total mass loss increased from 40 ± 9 Gt/y in 1979–1990 to 50 ± 14 Gt/y in 1989–2000, 166 ± 18 Gt/y in 1999–2009, and 252 ± 26 Gt/y in 2009–2017.”  “The contribution to sea-level rise from Antarctica averaged 3.6 ± 0.5 mm per decade with a cumulative 14.0 ± 2.0 mm since 1979”. ↩

2. 17b.

   Table 1, page 1096:  The Denman row gives a drainage-basin area of 265.5 thousand km² and a sea-level equivalent of 149 cm, the table's last column. ↩

Intergovernmental Panel on Climate Change.  “Summary for Policymakers.”  Climate Change 2021:  The Physical Science Basis, Contribution of Working Group I to the Sixth Assessment Report, 3–32.  Cambridge University Press.  2021.  The summary of the IPCC's 2021 physical-science assessment, approved line by line by government delegates.  It states the consensus position on observed warming, its causes, and climate sensitivity.

1. 18a.

   Section B.5.3, page 21:  “Relative to 1995–2014, the likely global mean sea level rise by 2100 is 0.28–0.55 m under the very low GHG emissions scenario (SSP1-1.9); 0.32–0.62 m under the low GHG emissions scenario (SSP1-2.6); 0.44–0.76 m under the intermediate GHG emissions scenario (SSP2-4.5); and 0.63–1.01 m under the very high GHG emissions scenario (SSP5-8.5)”. ↩

2. 18b.

   Section A.3.1, page 8:  “It is virtually certain that hot extremes (including heatwaves) have become more frequent and more intense across most land regions since the 1950s”.  Section A.3.2, page 8:  “The frequency and intensity of heavy precipitation events have increased since the 1950s over most land area for which observational data are sufficient for trend analysis (high confidence)”.  Section A.3.4, page 9:  “It is likely that the global proportion of major (Category 3–5) tropical cyclone occurrence has increased over the last four decades”.  “There is low confidence in long-term (multi-decadal to centennial) trends in the frequency of all-category tropical cyclones.” ↩

3. 18c.

   Section B.2.5, page 16:  “The Arctic is likely to be practically sea ice-free in September”.  “at least once before 2050 under the five illustrative scenarios considered in this report, with more frequent occurrences for higher warming levels.”  A footnote number after "September" in the original is left out. ↩

Loose, Brice et al.  “Evidence of an active volcanic heat source beneath the Pine Island Glacier.”  Nature Communications 9:2431.  2018.  A study using helium-3 from the earth's mantle, measured in seawater in front of the Pine Island ice shelf in 2007 and 2014, to detect volcanic heat under the glacier and compare it with the heat of the ocean water that melts the shelf.

1. 19a.

   Section Results, page 5:  “Based on the observed 3He excesses, the mantle-derived heat at the front of the ice shelf cavity is 32 ± 12 J kg−1 of seawater. This excess heat is small compared to the heat content of CDW”.  “(ca. 12 kJ kg−1), demonstrating that volcanic heat does not contribute significantly to the glacial melt observed in the ocean at the front of the ice shelf.”  Section Introduction, page 2:  “Presently, the greatest contributor to ice shelf instability around Antarctica appears to be an increase in ocean heat supply to the cavities of Antarctic ice shelves”.  CDW is Circumpolar Deep Water, the warm water that reaches under the ice shelf.  Superscript reference numbers are left out. ↩

Farinotti, Daniel et al.  “A consensus estimate for the ice thickness distribution of all glaciers on Earth.”  Nature Geoscience 12:168–173.  2019.  An estimate of the ice in the world's mountain glaciers and ice caps, combining up to five models.  By design it leaves out the Greenland and Antarctic ice sheets.

1. 20a.

   Section Abstract:  “Here we use an ensemble of up to five models to provide a consensus estimate for the ice thickness distribution of all the about 215,000 glaciers outside the Greenland and Antarctic ice sheets.”  “We find a total volume of 158 ± 41 × 10^3 km^3, which is equivalent to 0.32 ± 0.08 m of sea-level change when the fraction of ice located below present-day sea level (roughly 15%) is subtracted.” ↩

Brancato, V. et al.  “Grounding Line Retreat of Denman Glacier, East Antarctica, Measured With COSMO-SkyMed Radar Interferometry Data.”  Geophysical Research Letters 47:e2019GL086291.  2020.  Satellite radar measurements showing that the line where Denman Glacier leaves the bed and floats retreated 5.4 km between 1996 and 2017–2018, on the edge of the deepest trough in Antarctica.

1. 21a.

   Section Abstract:  “Denman Glacier, East Antarctica, holds an ice volume equivalent to a 1.5 m rise in global sea level.”  “If warm, modified Circumpolar Deep Water reaches the sub-ice-shelf cavity and continues to melt ice at a rate exceeding balance conditions, the potential exists for Denman Glacier to retreat irreversibly into the deepest, marine-based basin in Antarctica.” ↩

Associated Press.  U.N. official predicts disaster, says greenhouse effect could wipe some nations off map.  Jun 1989.  A wire story reporting an interview with Noel Brown, director of the New York office of the UN Environment Programme, the source of the "entire nations" quotation that circulates online.  Mirror:  Archive.org

1. 22a.

   Paragraph 1:  “A senior U.N. environmental official says entire nations could be wiped off the face of the Earth by rising sea levels if the global warming trend is not reversed by the year 2000.” ↩

2. 22b.

   Paragraph 10:  “The most conservative scientific estimate that the Earth’s temperature will rise 1 to 7 degrees in the next 30 years, said Brown.” ↩

Annual global means from HadCRUT5 version 5.2.0.0 ⁴¹, Berkeley Earth ⁴³ and GISTEMP v4 ⁴², each re-expressed as the difference from its own 1850–1900 mean (1880–1900 for GISTEMP).  Means:  2011–2020, 1.12, 1.18, 1.05 °C;  2015–2024, 1.27, 1.33, 1.20;  1940–1949, 0.33, 0.33, 0.26;  2024, 1.55, 1.62, 1.50.  Least-squares trends in °C per decade:  1975–2025, 0.209, 0.208 (to 2024), 0.207;  2000–2025, 0.254, 0.257, 0.265;  1988–2006, 0.209, 0.209, 0.193;  1910–1940, 0.167, 0.130, 0.113;  1940–1975, −0.032, −0.017, −0.019;  1860–1880, 0.134 and 0.119 for HadCRUT5 and Berkeley. ↩

Flannery, Tim, and Sally (interviewer) Sara.  “Interview with Professor Tim Flannery.”  Landline, ABC Television.  Feb 11, 2007.  The transcript of a television interview with the mammalogist Tim Flannery, then Australian of the Year, about climate change and Australian farming.  Mirror:  Archive.org

1. 24a.

   Flannery's first answer:  “So even the rain that falls isn't actually going to fill our dams and our river systems, and that's a real worry for the people in the bush. If that trend continues then I think we're going to have serious problems, particularly for irrigation.” ↩

Gore, Al.  “Nobel Lecture.”  NobelPrize.org.  Dec 10, 2007.  Al Gore's lecture in Oslo on receiving the Nobel Peace Prize jointly with the IPCC.

1. 25a.

   The passage on the North Polar ice cap:  “Last September 21, as the Northern Hemisphere tilted away from the sun, scientists reported with unprecedented distress that the North Polar ice cap is “falling off a cliff.” One study estimated that it could be completely gone during summer in less than 22 years. Another new study, to be presented by U.S. Navy researchers later this week, warns it could happen in as little as 7 years.”  “Seven years from now.” ↩

Fetterer, F. et al.  Sea Ice Index, version 4, Northern Hemisphere monthly extent, September.  2026.  The standard satellite record of Arctic sea-ice extent and area from 1979, here for September, the month of the yearly minimum.

1. 26a.

   September extent, million km²:  1980, 7.67;  2007, 4.27;  2012, 3.57;  2014, 5.22;  2020, 4.00;  2026, 4.81. ↩

Peterson, Thomas C. et al.  “The myth of the 1970s global cooling scientific consensus.”  Bulletin of the American Meteorological Society 89(9):1325–1337.  2008.  A survey of the peer-reviewed climate literature of 1965–1979 by a NOAA climatologist, a climate modeller and a science journalist, classifying each paper by whether it predicted cooling, warming, or neither.

1. 27a.

   Figures 1, caption, page 1333:  “During the period from 1965 through 1979, our literature survey found 7 cooling, 20 neutral, and 44 warming papers.” ↩

Broecker, Wallace S.  “Climatic Change:  Are We on the Brink of a Pronounced Global Warming?”  Science 189(4201):460–463.  Aug 8, 1975.  A short paper by the Columbia geochemist predicting that CO2 warming would soon overtake a natural cooling cycle.  It is cited here for its title. ↩

Zhu, Zaichun et al.  “Greening of the Earth and its drivers.”  Nature Climate Change 6:791–795.  2016.  An analysis of three satellite records of leaf area from 1982 to 2009, with ten ecosystem models used to divide the greening among CO2, nitrogen deposition, climate and land use.

1. 29a.

   Section Abstract:  “We show a persistent and widespread increase of growing season integrated LAI (greening) over 25% to 50% of the global vegetated area, whereas less than 4% of the globe shows decreasing LAI (browning). Factorial simulations with multiple global ecosystem models suggest that CO 2 fertilization effects explain 70% of the observed greening trend”. ↩

Campbell, J. E. et al.  “Large historical growth in global terrestrial gross primary production.”  Nature 544:84–87.  2017.  An estimate of how much land-plant photosynthesis grew in the twentieth century, from carbonyl sulphide, a gas that plants take up along with CO2, recorded in Antarctic ice, firn and air.

1. 30a.

   Page 84:  “We find that the observation-based COS record is most consistent with simulations of climate and the carbon cycle that assume large GPP growth during the twentieth century (31% ± 5% growth; mean ± 95% confidence interval).” ↩

Doo, Steve S. et al.  “Ocean acidification effects on in situ coral reef metabolism.”  Scientific Reports 9:12067.  2019.  A three-week field experiment that pumped CO2-enriched seawater over a patch of back reef at Mo'orea, French Polynesia, to about two and a half times today's level, measuring how fast the reef community built skeleton and photosynthesised.

1. 31a.

   Section Abstract:  “Our results show a decrease in 24-h net community calcification (NCC) under high pCO2, and a reduction in nighttime NCC that attenuated and eventually reversed over 21-d.”  Section Results and Discussion:  “While recent work has shown little acclimatization potential of reef calcifiers to OA”.  “The proximal mechanism(s) underlying this response are unknown”. ↩

Knowlton, Nancy.  “The Great Barrier Reef – Going, Going, Gone???”  Smithsonian Ocean, Personal Perspectives.  2012.  A short opinion piece by the Smithsonian's chair of marine science, reporting a study that found half the reef's coral lost between 1986 and 2012 and projecting the trend forward.  Mirror:  Archive.org

1. 32a.

   “Between 1986 and 2012, over half of the living coral has been lost. If current trends continue, over 90 percent or more of the living coral will be gone from the central and southern parts of the reef in just 10 years.” ↩

Australian Institute of Marine Science.  Long-Term Monitoring Program, annual summary report on coral reef condition, 2025–26.  Aug 11, 2026.  The yearly report of Australia's government reef-survey programme, which has measured hard coral cover on the same reefs since 1986, here as released and reposted by the Global Coral Reef Monitoring Network.

1. 33a.

   “Hard coral cover increased slightly across two of the three regions, in line with long term averages from the past 40 years.”  “Hard coral cover remains close to the long term 40-year averages recorded by the LTMP.” ↩

Kamenos, Nicholas A., and Sebastian J. Hennige.  “Reconstructing Four Centuries of Temperature-Induced Coral Bleaching on the Great Barrier Reef.”  Frontiers in Marine Science 5:283.  2018.  A reconstruction of bleaching years on the Great Barrier Reef from 1620 to 2001, using growth rates in 44 overlapping cores of a heat-tolerant coral as a record of heat stress.

1. 34a.

   Section Conclusion:  “Here we show that corals bleached pre-industrially, but subsequently, bleaching has intensified.” ↩

Crockford, Susan J.  “The State of the Polar Bear Report 2023.”  Global Warming Policy Foundation, Briefing 67.  2024.  A yearly report by a Canadian zoologist for a British skeptical think tank, arguing that polar bear numbers are higher than the official estimate.  It gives the official figure alongside her own revised tally.

1. 35a.

   Section Global population:  “The latest official estimate for the global population, from 17 October 2023, is the PBSG estimate of 26,000 (range 22,000–31,000), arrived at in 2015 and unadjusted since then.”  “plausibly brought the mid-point total to just over 32,000”. ↩

IUCN SSC Polar Bear Specialist Group.  Population Status.  2024.  The international specialist group's table of the nineteen to twenty polar bear subpopulations, with their latest counts, trends and the methods behind them.

1. 36a.

   Section Baffin Bay:  “Due to evidence that the sampling design and environmental conditions likely resulted in an underestimate of abundance in the 1990s, the estimates of abundance for the 1990s and 2010s are not directly comparable and trend cannot be determined.” ↩

Royal Commission into National Natural Disaster Arrangements.  Report.  Commonwealth of Australia.  Oct 2020.  The Australian government's royal commission into the 2019–20 bushfire season, which gathered the states' and federal government's burnt-area and casualty figures.

1. 37a.

   Section Foreword:  “Over 24 million hectares were burnt.”  “Tragically, 33 people died and extensive smoke coverage across much of eastern Australia may have caused many more deaths.” ↩

Editors-in-Chief, The European Physical Journal Plus.  “Retraction Note:  A critical assessment of extreme events trends in times of global warming.”  The European Physical Journal Plus 138.  Aug 23, 2023.  The journal's notice retracting the 2022 paper by Gianluca Alimonti, Luigi Mariani, Franco Prodi and others, which had argued that most kinds of extreme weather show no trend.

1. 38a.

   “Concerns were raised regarding the selection of the data, the analysis and the resulting conclusions of the article. The authors were invited to submit an addendum to the article, but post publication review of the concerns with the article and the submitted addendum concluded that the addendum was not suitable for publication and that the conclusions of the article were not supported by available evidence or data provided by the authors.”  “The authors disagree with this retraction.” ↩

Kench, Paul S. et al.  “Patterns of island change and persistence offer alternate adaptation pathways for atoll nations.”  Nature Communications 9:605.  2018.  A study of shoreline change on all 101 reef islands of Tuvalu, using remotely sensed images over about four decades, measuring how each island's area changed while the local sea level rose.

1. 39a.

   Page 1:  “Results highlight a net increase in land area in Tuvalu of 73.5 ha (2.9%), despite sea-level rise, and land area increase in eight of nine atolls.”  “a period when local sea level has risen at twice the global average (~3.90 ± 0.4 mm.yr−1)”. ↩

2. 39b.

   Page 5:  “Under these higher sea-level projections it is unclear whether islands will continue to maintain their size”. ↩

Duvat, Virginie K. E.  “A global assessment of atoll island planform changes over the past decades.”  WIREs Climate Change 10(1):e557.  2019.  A review of published measurements of how the area of atoll islands changed over recent decades, pooling 30 atolls in the Pacific and Indian Oceans.

1. 40a.

   Section Abstract:  “A reanalysis of available data, which cover 30 Pacific and Indian Ocean atolls including 709 islands, reveals that no atoll lost land area and that 88.6% of islands were either stable or increased in area, while only 11.4% contracted.” ↩

Met Office Hadley Centre;  Climatic Research Unit, University of East Anglia.  HadCRUT5 analysis, global annual summary series, version 5.2.0.0.  2026.  The British global surface temperature record, combining land stations from the Climatic Research Unit with the Hadley Centre's sea-surface temperatures, 1850 to the present, as anomalies from 1961–1990 with uncertainty limits. ↩

NASA Goddard Institute for Space Studies.  GISTEMP v4, global land-ocean temperature index.  2026.  NASA's global surface temperature record from 1880, as monthly and annual anomalies from 1951–1980. ↩

Berkeley Earth.  Global land and ocean temperature, annual summary.  2026.  The independent Berkeley Earth global surface record from 1850, built with its own station selection and statistical method.  This file runs to 2024. ↩

Spencer, Roy W. et al.  UAH global temperature, lower troposphere, version 6.1, monthly anomalies.  2026.  The satellite record of lower-atmosphere temperature built by Spencer and Christy from microwave sounders, December 1978 to the present, by region, with its own trend line. ↩

Spencer, Roy W. et al.  UAH global temperature, mid-troposphere, version 6.1, monthly anomalies.  2026.  The same satellite record for the middle troposphere, by region, including the tropics from 20° S to 20° N. ↩

Remote Sensing Systems.  RSS lower troposphere temperature, version 4.0, monthly time series.  2026.  The second satellite record of lower-atmosphere temperature, from the same instruments as UAH but with different processing, 1979 to the present. ↩

Remote Sensing Systems.  RSS middle troposphere temperature, version 4.0, monthly time series.  2026.  The RSS record for the middle troposphere, by region, including the tropics. ↩

Permanent Service for Mean Sea Level.  Annual mean sea level, Sydney, Fort Denison 2, station 196, revised local reference.  2026.  The yearly tide-gauge record for Sydney Harbour from 1915, the gauge CMI cites, as kept by the international tide-gauge archive. ↩