State of the UK Climate 2019

This report provides a summary of the UK weather and climate through the calendar year 2019, alongside the historical context for a number of essential climate variables. This is the sixth in a series of annual ‘State of the UK Climate’ publications and an update to the 2018 report (Kendon et al., 2019). It provides an accessible, authoritative and up‐to‐date assessment of UK climate trends, variations and extremes based on the most up to date observational datasets of climate quality

State of the <scp>UK</scp> Climate 2020

INTRODUCTION: This report provides a summary of the UK weather and climate through the calendar year 2020, alongside the historical context for a number of essential climate variables. This is the seventh in a series of annual ‘State of the UK climate’ publications and an update to the 2019 report (Kendon et al., 2020). It provides an accessible, authoritative and up‐to‐date assessment of UK climate trends, variations and extremes based on the most up to date observational datasets of climate quality. The majority of this report is based on observations of temperature, precipitation, sunshine and wind speed from the UK land weather station network as managed by the Met Office and a number of key partners and co‐operating volunteers. The observations are carefully managed such that they conform to current best practice observational standards as defined by the World Meteorological Organization (WMO). The observations also pass through a range of quality assurance procedures at the Met Office before application for climate monitoring. Time series of near‐coast sea‐surface temperature and sea‐level are also presented and in addition a short section on phenology which provides dates of first leaf and bare tree indicators for four common shrub or tree species. National and regional statistics in this report are from the HadUK‐Grid dataset which is the principal source of data (Hollis et al., 2019). Temperature and rainfall series from this dataset extend back to 1884 and 1862, respectively. Details of the datasets used throughout this report and how the various series which are presented are derived are provided in the appendices. The report presents summary statistics for the most recent year 2020 against the most recent decade 2011–2020, the most recent 30‐year reference period (1981–2010) and the climate reference period 1961–1990. The full series provide longer‐term context, while a comparison is also made to centennial averages for the Central England Temperature series. The decade 2011–2020 is a non‐standard reference period, but it provides a 10‐year ‘snapshot’ of the most recent experience of the UK's climate and how that compares to historical records. This means differences between 2011 and 2020 and 30‐year reference periods may reflect shorter‐term decadal variations as well as long‐term trends. For this annual publication, the most recent decade (currently 2011–2020) changes every year, while the most recent 30‐year reference period (currently 1981–2010) changes every decade. For next year's report, the most recent 30‐year reference period will change from 1981–2010 to 1991–2020, while the climate reference period 1961–1990 will be retained. However, this report also includes a brief summary of key differences between preliminary 1991–2020 and 1981–2010 averages for temperature and rainfall. Throughout the report's text the terms “above normal” and “above average” and so on refer to the 1981–2010 baseline reference period unless otherwise stated. The majority of maps in this report show the year 2020 relative to the 1981–2010 reference period—that is, they are anomaly maps which show the spatial variation in this difference from average. Maps of actual values are in most cases not displayed because these are dominated by the underlying climatology, which for this report is of a lesser interest than the year‐to‐year variability. These data are presented to show what has happened in recent years, not necessarily what is expected to happen in a changing climate. Values quoted in tables throughout this report are rounded, but where the difference between two such values is quoted in the text (e.g., comparing the most recent decade with 1981–2010), this difference is calculated from the original unrounded values. Updates Compared to State of UK Climate 2019 A chart showing global surface temperature has been added. The section on sea level rise has been revised. A section summarizing key differences between preliminary 1991–2010 and 1981–2010 averages has been added. Feedback We would welcome suggestions or recommendations for future annual publications of this report. Please send any feedback to the Met Office at [email protected] This State of the UK Climate report was supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra

A comparison of characterisation and modelling approaches to predict dissolved metal concentrations in soils

Environmental contextIt is useful to know the concentration of ‘labile’, or chemically active, metal in soils because it can be used to predict metal solubility and environmental impact. Several methods for extracting the labile metal from soils have been proposed, and here we have tested two of these to see how well the resulting data can be used to model metal solubility. Such mixed approaches can be applied to different soil types with the potential to model metal solubility over large areas.RationalePredicting terrestrial metal dynamics requires modelling of metal solubility in soils. Here, we test the ability of two geochemical speciation models that differ in complexity and data requirements (WHAM/Model VII and POSSMs), to predict metal solubility across a broad range of soil properties, using differing estimates of the labile soil metal concentration.MethodologyUsing a dataset of UK soils, we characterised basic properties including pH and the concentrations of humic substances, mineral oxides and metals. We estimated labile metal by extraction with 0.05 mol L−1 Na2H2EDTA and by multi-element isotopic dilution (E-value). Dissolved concentrations of Ni, Cu, Zn, Cd and Pb were estimated in 0.01 mol L−1 Ca(NO3)2 soil suspensions using the total metal ({M}total), the EDTA-extracted pool ({M}EDTA) and the E-value ({M}E) as alternative estimates of the chemically reactive metal concentration.ResultsConcentrations of {M}EDTA were highly correlated with values of {M}E, although some systematic overestimation was seen. Both WHAM/Model VII and POSSMs provided reasonable predictions when {M}EDTA or {M}E were used as input. WHAM/Model VII predictions were improved by fixing soil humic acid to a constant proportion of the soil organic matter, instead of the measured humic and fulvic acid concentrations.DiscussionThis work provides further evidence for the usefulness of speciation modelling for predicting soil metal solubility, and for the usefulness of EDTA-extracted metal as a surrogate for the labile metal pool. Predictions may be improved by more robust characterisation of the soil and porewater humic substance content and quality

Chemical extraction of labile metal from soils : an isotopic investigation

The 2012 annual meeting of the British Society of Soil Science will be hosted by the University of Nottingham. The meeting will focus on the required contributions and potential opportunities for soil science with respect to Global Food Security. The forecasted increasingly variable weather patterns will influence the environment and its ability to support sustainable food production. Major challenges include water scarcity, a decrease availability of key inputs to food production, managing carbon and differing local impacts of climate change. Soil science is at the heart of all these issues. The meeting will consist of two days with four sessions strongly related to the main theme and a an un-themed session where presentations from any aspect of soil science are encouraged

Lability and solubility of Ni, Cu, Zn, Cd and Pb in UK soils

Currently, total metal concentrations (MTotal) are used to assess the toxicity risks of soil metal to human and environmental health. However, not all soil metal is available over the timescales relevant for toxicity, and therefore use of MTotal may overestimate the risks. Measurements of labile soil metal can be used (1) to define critical limits that reflect the amount of metal in the soil that is ‘potentially bioavailable’ to plants and soil organisms that take up metal from the soil solution and (2) as inputs to geochemical models, for the purpose of predicting soil metal solubility, speciation and dynamics, which are also important for risk assessment purposes. Labile soil metal can be measured using isotopic dilution and chemical extraction methods, but these measurements are not widely available for the soils used in toxicity studies, or for the soils included in national scale geochemical surveys. Therefore the objectives of this study were: (1) to assess the current multi-element stable isotopic dilution methodology for measuring labile Ni, Cu, Zn, Cd and Pb in soils (E values), (2) to evaluate how E values compare to alternative measurements of labile soil metal, (3) to calculate how E values relate to soil properties in order to form predictive algorithms for E values and (4) to use E values and geochemical modelling to predict soil metal solubility. E values (for 6 soils) were found to be operationally defined by the isotope spike contact time used in the multi-element stable isotopic dilution method. However, between 3 and 5 days of isotope spike contact time the % E values increased by less than 5 % for all soil-metal combinations tested. The multi-element spike solution caused a significant decrease in the pH, and increase in the solution concentrations of Ni, Cu, Zn, Cd and Pb in the suspensions of one soil, and Cu in all 6 soils. Metal concentrations solubilised by eight commonly used extractants (MExt) were directly compared to the E values measured in four soils. The extractants used were 0.21 M and 0.43 M HNO3, 0.43 M CH3COOH, 0.01 and 0.05 M Na2H2EDTA, 5 % TMAH, 0.55 M NaOH, 0.5 M NaHCO3 and 0.5 M NH4H2PO4. The 0.01 M Na2H2EDTA extractant provided the best overall analogue for E value. The concentrations of isotopically exchangeable metal were also measured under the conditions of the 0.43 M iii HNO3, 0.43 M CH3COOH, 0.05 M Na2H2EDTA and 1 M CaCl2 extractants (combined isotopic dilution-chemical extraction assay; EExt). Comparison of MExt, E value and EExt revealed whether the extractants (1) mobilised any non-labile soil metal and (2) solubilised all extraction-labile soil metal. The only extractant to consistently solubilise all extraction-labile soil metal was 0.05 M Na2H2EDTA, however this extractant also caused mobilisation of non-labile metal in the three out of the four soils. Predictive algorithms, using the soil characteristics log MP-Total (pseudo-total), pH and LOI, explained more than 80 % of the variability in Ni, Cu, Zn, Cd and Pb log E values (109 soils), but only 53 %, 6 %, 47 %, 42 % and 56 % of the variability in Ni, Cu, Zn, Cd and Pb % E values respectively. Predictive algorithms using 0.05 M Na2H2EDTA MExt and pH explained more than 90 % of the variability in Ni, Cu, Zn, Cd and Pb log E values. Soil solution metal concentrations were predicted using the geochemical assemblage model WHAM/Model VII, using either MTotal, MExt or E values as model inputs, and compared to solution concentrations measured in 0.01 M Ca(NO3)2 soil suspensions. Using MTotal as an input generally resulted in overestimation of the soluble concentrations of all five metals, but using E values improved model predictions

Measurement of labile metal in soils. Chemical extraction and isotopic dilution data. NERC Environmental Information Data Centre. doi:10.5285/4ecdb4b3-3af6-4c92-abbb-20a330be398b

Garforth, J. ; Bailey, E.H.; Tye, A.M.; Young, S.D.; Lofts, S. (2013). Measurement of labile metal in soils. Chemical extraction and isotopic dilution data. NERC Environmental Information Data Centre. doi:10.5285/4ecdb4b3-3af6-4c92-abbb-20a330be398

State of the UK Climate 2021

INTRODUCTION: This report provides a summary of the UK weather and climate through the calendar year 2021, alongside the historical context for a number of essential climate variables. This is the eighth in a series of annual “State of the UK Climate” publications and an update to the 2020 report (Kendon et al., 2021). It provides an accessible, authoritative and up‐to‐date assessment of UK climate trends, variations and extremes based on the most up‐to‐date observational datasets of climate quality. The majority of this report is based on observations of temperature, precipitation, sunshine and wind speed from the UK land weather station network as managed by the Met Office and a number of key partners and co‐operating volunteers. The observations are carefully managed such that they conform to current best‐practice observational standards as defined by the World Meteorological Organization (WMO). The observations also pass through a range of quality assurance procedures at the Met Office before application for climate monitoring. Time series of near‐coast sea‐surface temperature and sea level are also presented and in addition there is a short section on phenology which provides dates of “first leaf” and “bare tree” indicators for four common shrub or tree species. The reliance of this report on these observations highlights the ongoing need to adequately maintain the observation networks, in particular the UK land weather station network, into the future, to ensure that this UK climate monitoring capability is continued. National and regional statistics in this report are from the HadUK‐Grid dataset which is the principal source of data (Hollis et al., 2019). Temperature and rainfall series from this dataset extend back to 1884 and 1836, respectively. Details of the datasets used throughout this report and how the various series which are presented are derived are provided in the appendices. A recent development to the underpinning dataset has been the inclusion of several million recently digitized historical monthly rainfall data (Hawkins et al., 2022). These data significantly improve the geographical representation of rainfall before 1960 and allow for the extension of the national series back to 1836. The report presents summary statistics for the most recent year 2021 against the most recent decade 2012–2021, and following World Meteorological Organization (WMO) climatological best‐practice against the most recent 30‐year standard climate normal period 1991–2020 and the baseline period 1961–1990 (WMO, 2017). These two 30‐year reference periods do not overlap. The full series provide longer‐term context, while a comparison is also made to centennial averages for the Central England Temperature series. The decade 2012–2021 is a nonstandard reference period, but it provides a 10‐year “snapshot” of the most recent experience of the UK's climate and how that compares to historical records. This means that differences between 2012–2021 and the 30‐year reference periods may reflect shorter‐term decadal variations as well as long‐term trends. For this annual publication, the most recent decade (currently 2012–2021) changes every year, while the most recent 30‐year reference period changes every decade. For this year's report, we use the 30‐year reference period 1991–2020 for the first time, updated from 1981 to 2010 for last year's report (Kendon et al., 2021). The baseline reference period 1961–1990 is retained, as this is a consistent reference period used not only throughout the series of State of UK Climate reports but also more widely for historical comparison, climate change monitoring and climate modelling following the WMO best‐practice. Throughout the report's text the terms “above normal,” “above average,” etc. refer to the 1991–2020 reference period unless otherwise stated. The majority of maps in this report show the year 2021 relative to the 1991–2020 reference period, that is, they are anomaly maps which show the spatial variation in this difference from average. Maps of actual values are in most cases not displayed because these are dominated by the underlying climatology, which for this report is of a lesser interest than the year‐to‐year variability. These data are presented to show what has happened in recent years, not necessarily what is expected to happen in a changing climate. Values quoted in tables throughout this report are rounded, but where the difference between two such values is quoted in the text (e.g., comparing the most recent decade with 1991–2020), this difference is calculated from the original unrounded values. Updates compared to state of UK climate 2020: The most recent 30‐year reference period is changed from 1981–2010 to 1991–2020. The dataset used to generate the summer North Atlantic Oscillation index is changed. Figures showing the UK average daily mean temperature and daily rainfall for each day of the year are added. A figure showing UK annual mean wind speed from 1969 has been added. The sea‐level section has been revised. Feedback: We would welcome suggestions or recommendations for future annual publications of this report. Please send any feedback to the Met Office at [email protected]. This State of the UK Climate report was supported by the Met Office Hadley Centre Climate Programme funded by BEIS and Defra

Global Climate

In 2021, both social and economic activities began to return towards the levels preceding the COVID-19 pandemic for some parts of the globe, with others still experiencing restrictions. Meanwhile, the climate has continued to respond to the ongoing increase in greenhouse gases and resulting warming. La Niña, a phenomenon which tends to depress global temperatures while changing rainfall patterns in many regions, prevailed for all but two months of the year. Despite this, 2021 was one of the six-warmest years on record as measured by global mean surface temperature with an anomaly of between +0.21° and +0.28°C above the 1991–2020 climatology. Lake surface temperatures were their highest on record during 2021. The number of warm days over land also reached a new record high. Exceptional heat waves struck the Pacific Coast of North America, leading to a new Canadian maximum temperature of 49.6°C at Lytton, British Columbia, on 29 June, breaking the previous national record by over 4°C. In Death Valley, California, the peak temperature reached 54.4°C on 9 July, equaling the temperature measured in 2020, and the highest temperature recorded anywhere on the globe since at least the 1930s. Over the Mediterranean, a provisional new European record of 48.8°C was set in Sicily on 11 August. In the atmosphere, the annual mean tropospheric temperature was among the 10 highest on record, while the stratosphere continued to cool. While La Niña was present except for June and July, likely influencing Australia’s coolest year since 2012 and wettest since 2016, other modes of variability played important roles. A negative Indian Ocean dipole event became established during July, associated with a warmer east and cooler west Indian Ocean. Northern Hemisphere winters were affected by a negative phase of the North Atlantic Oscillation at both the beginning and end of 2021. In the Southern Hemisphere, a very strong positive Southern Annular Mode (also known as the Antarctic Oscillation) contributed to New Zealand’s record warm year and to very cold temperatures over Antarctica. Land surface winds continued a slow reversal from the multi-decadal stilling, and over the ocean wind speeds were at their highest in almost a decade. La Niña conditions had a clear influence on the regional patterns of many hydrological variables. Surface specific humidity and total column water vapor over land and ocean were higher than average in almost all datasets. Relative humidity over land reached record or near-record low saturation depending on the dataset, but with mixed signals over the ocean. Satellite measurements showed that 2021 was the third cloudiest in the 19-year record. The story for precipitation was mixed, with just below-average mean precipitation falling over land and below-average mean precipitation falling over the ocean, while extreme precipitation was generally more frequent, but less intense, than average. Differences between means and extremes can be due to several factors, including using different indices, observing periods, climatological base reference periods, and levels of spatial completeness. The sharp increase in global drought area that began in mid-2019 continued in 2021, reaching a peak in August with 32% of global land area experiencing moderate or worse drought, and declining slightly thereafter. Arctic permafrost temperatures continued to rise, reaching record values at many sites, and the thickness of the layer which seasonally thaws and freezes also increased over 2020 values in a number of regions. It was the 34th-consecutive year of mass balance loss for alpine glaciers in mountainous regions, with glaciers on average 25 m thinner than in the late 1970s. And the duration of lake ice in the Northern Hemisphere was the fourth lowest in situ record dating back to 1991. The atmospheric concentrations of the major long-lived greenhouse gases, CO2, CH4, and N2O, all reached levels not seen in at least the last million years and grew at near-record rates in 2021. La Niña conditions did not appear to have any appreciable impact on their growth rates. The growth rate for CH4, of 17 ppb yr−1, was similar to that for 2020 and set yet another record, although the causes for this post-2019 acceleration are unknown presently. Overall, CO2 growth continues to dominate the increase in global radiative forcing, which increased from 3.19 to 3.23 W m−2 (watts per square meter) during the year. In 2021, stratospheric ozone did not exhibit large negative anomalies, especially near the poles, unlike 2020, where large ozone depletions appeared, mainly from dynamical effects. The positive impact of reductions in emissions of ozone depleting substances can be seen most clearly in the upper stratosphere, where such dynamical effects are less pronounced. It was the fourth-lowest fire year since global records began in 2003, though extreme regional fire activity was again seen in North America and also in Siberia; as in 2020, the effects of wildfires in these two regions led to locally large regional positive anomalies in tropospheric aerosol and carbon monoxide abundance. Vegetation is responding to the higher global mean temperatures, with the satellite-derived measures for the Northern Hemisphere for 2021 rated among the earliest starts of the growing season and the latest end of the season on record. The first bloom date for cherry trees in Kyoto, Japan, broke a 600-year record set in 1409. This year we welcome a sidebar on the global distribution of lightning, which has been recently declared an essential climate variable (ECV) by the Global Climate Observing System (GCOS). Time series and anomaly maps from many of the variables described in this chapter can be found in Plates 1.1 and 2.1. As with other chapters, many of the sections have moved from the previous 1981–2010 to the new 1991–2020 climatological reference period, in line with WMO recommendations (see Chapter 1). This is not possible for all datasets, as it is dependent on their length of record or legacy processing methods. While anomalies from the new climatology period are not so easily comparable with previous editions of this report, they more clearly highlight deviations from more recent conditions

State of the climate in 2022: introduction

Earth’s global climate system is vast, complex, and intricately interrelated. Many areas are influenced by global-scale phenomena, including the “triple dip” La Niña conditions that prevailed in the eastern Pacific Ocean nearly continuously from mid-2020 through all of 2022; by regional phenomena such as the positive winter and summer North Atlantic Oscillation that impacted weather in parts the Northern Hemisphere and the negative Indian Ocean dipole that impacted weather in parts of the Southern Hemisphere; and by more localized systems such as high-pressure heat domes that caused extreme heat in different areas of the world. Underlying all these natural short-term variabilities are long-term climate trends due to continuous increases since the beginning of the Industrial Revolution in the atmospheric concentrations of Earth’s major greenhouse gases.In 2022, the annual global average carbon dioxide concentration in the atmosphere rose to 417.1±0.1 ppm, which is 50% greater than the pre-industrial level. Global mean tropospheric methane abundance was 165% higher than its pre-industrial level, and nitrous oxide was 24% higher. All three gases set new record-high atmospheric concentration levels in 2022.Sea-surface temperature patterns in the tropical Pacific characteristic of La Niña and attendant atmospheric patterns tend to mitigate atmospheric heat gain at the global scale, but the annual global surface temperature across land and oceans was still among the six highest in records dating as far back as the mid-1800s. It was the warmest La Niña year on record. Many areas observed record or near-record heat. Europe as a whole observed its second-warmest year on record, with sixteen individual countries observing record warmth at the national scale. Records were shattered across the continent during the summer months as heatwaves plagued the region. On 18 July, 104 stations in France broke their all-time records. One day later, England recorded a temperature of 40°C for the first time ever. China experienced its second-warmest year and warmest summer on record. In the Southern Hemisphere, the average temperature across New Zealand reached a record high for the second year in a row. While Australia’s annual temperature was slightly below the 1991–2020 average, Onslow Airport in Western Australia reached 50.7°C on 13 January, equaling Australia's highest temperature on record.While fewer in number and locations than record-high temperatures, record cold was also observed during the year. Southern Africa had its coldest August on record, with minimum temperatures as much as 5°C below normal over Angola, western Zambia, and northern Namibia. Cold outbreaks in the first half of December led to many record-low daily minimum temperature records in eastern Australia.The effects of rising temperatures and extreme heat were apparent across the Northern Hemisphere, where snow-cover extent by June 2022 was the third smallest in the 56-year record, and the seasonal duration of lake ice cover was the fourth shortest since 1980. More frequent and intense heatwaves contributed to the second-greatest average mass balance loss for Alpine glaciers around the world since the start of the record in 1970. Glaciers in the Swiss Alps lost a record 6% of their volume. In South America, the combination of drought and heat left many central Andean glaciers snow free by mid-summer in early 2022; glacial ice has a much lower albedo than snow, leading to accelerated heating of the glacier. Across the global cryosphere, permafrost temperatures continued to reach record highs at many high-latitude and mountain locations.In the high northern latitudes, the annual surface-air temperature across the Arctic was the fifth highest in the 123-year record. The seasonal Arctic minimum sea-ice extent, typically reached in September, was the 11th-smallest in the 43-year record; however, the amount of multiyear ice—ice that survives at least one summer melt season—remaining in the Arctic continued to decline. Since 2012, the Arctic has been nearly devoid of ice more than four years old.In Antarctica, an unusually large amount of snow and ice fell over the continent in 2022 due to several landfalling atmospheric rivers, which contributed to the highest annual surface mass balance, 15% to 16% above the 1991–2020 normal, since the start of two reanalyses records dating to 1980. It was the second-warmest year on record for all five of the long-term staffed weather stations on the Antarctic Peninsula. In East Antarctica, a heatwave event led to a new all-time record-high temperature of −9.4°C—44°C above the March average—on 18 March at Dome C. This was followed by the collapse of the critically unstable Conger Ice Shelf. More than 100 daily low sea-ice extent and sea-ice area records were set in 2022, including two new all-time annual record lows in net sea-ice extent and area in February.Across the world’s oceans, global mean sea level was record high for the 11th consecutive year, reaching 101.2 mm above the 1993 average when satellite altimetry measurements began, an increase of 3.3±0.7 over 2021. Globally-averaged ocean heat content was also record high in 2022, while the global sea-surface temperature was the sixth highest on record, equal with 2018. Approximately 58% of the ocean surface experienced at least one marine heatwave in 2022. In the Bay of Plenty, New Zealand’s longest continuous marine heatwave was recorded.A total of 85 named tropical storms were observed during the Northern and Southern Hemisphere storm seasons, close to the 1991–2020 average of 87. There were three Category 5 tropical cyclones across the globe—two in the western North Pacific and one in the North Atlantic. This was the fewest Category 5 storms globally since 2017. Globally, the accumulated cyclone energy was the lowest since reliable records began in 1981. Regardless, some storms caused massive damage. In the North Atlantic, Hurricane Fiona became the most intense and most destructive tropical or post-tropical cyclone in Atlantic Canada’s history, while major Hurricane Ian killed more than 100 people and became the third costliest disaster in the United States, causing damage estimated at $113 billion U.S. dollars. In the South Indian Ocean, Tropical Cyclone Batsirai dropped 2044 mm of rain at Commerson Crater in Réunion. The storm also impacted Madagascar, where 121 fatalities were reported.As is typical, some areas around the world were notably dry in 2022 and some were notably wet. In August, record high areas of land across the globe (6.2%) were experiencing extreme drought. Overall, 29% of land experienced moderate or worse categories of drought during the year. The largest drought footprint in the contiguous United States since 2012 (63%) was observed in late October. The record-breaking megadrought of central Chile continued in its 13th consecutive year, and 80-year record-low river levels in northern Argentina and Paraguay disrupted fluvial transport. In China, the Yangtze River reached record-low values. Much of equatorial eastern Africa had five consecutive below-normal rainy seasons by the end of 2022, with some areas receiving record-low precipitation totals for the year. This ongoing 2.5-year drought is the most extensive and persistent drought event in decades, and led to crop failure, millions of livestock deaths, water scarcity, and inflated prices for staple food items.In South Asia, Pakistan received around three times its normal volume of monsoon precipitation in August, with some regions receiving up to eight times their expected monthly totals. Resulting floods affected over 30 million people, caused over 1700 fatalities, led to major crop and property losses, and was recorded as one of the world’s costliest natural disasters of all time. Near Rio de Janeiro, Brazil, Petrópolis received 530 mm in 24 hours on 15 February, about 2.5 times the monthly February average, leading to the worst disaster in the city since 1931 with over 230 fatalities.On 14–15 January, the Hunga Tonga-Hunga Ha'apai submarine volcano in the South Pacific erupted multiple times. The injection of water into the atmosphere was unprecedented in both magnitude—far exceeding any previous values in the 17-year satellite record—and altitude as it penetrated into the mesosphere. The amount of water injected into the stratosphere is estimated to be 146±5 Terragrams, or ∼10% of the total amount in the stratosphere. It may take several years for the water plume to dissipate, and it is currently unknown whether this eruption will have any long-term climate effect