Timothy Raymond Naish
1966 (age 56–57)
|University of Waikato
|Glaciology and climate science
| GNS Science
Victoria University Wellington
|High-resolution sequence stratigraphy, sedimentology, paleoecology, and chronology of the Pliocene-Pleistocene (c.2.6–1.7 Ma) Rangitikei Group, Wanganui Basin, New Zealand (1996)
Timothy Raymond Naishis a New Zealand glaciologist and climate scientist who has been a researcher and lecturer at Victoria University of Wellington and the Director of the Antarctic Research Centre, and in 2020 became a programme leader at the Antarctic Science Platform. Naish has researched and written about the possible effect of melting ice sheets in Antarctica on global sea levels due to high CO2 emissions causing warming in the Southern Ocean. He was instrumental in establishing and leading the Antarctica Drilling Project (ANDRILL), and a Lead Author on the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (2014).
Naish initially studied engineering at Waikato University but moved into earth sciences and gained skills in geological mapping and describing rocks, graduating with a BSc in 1988. He continued to study at Waikato University, completing a master's degree with first class honours in 1990and after working for while as a geologist with the Department of Scientific and Industrial Research (DSIR) completed his PhD in 1996. He worked as an Assistant Lecturer at University of Waikato, Earth Sciences, New Zealand (1990-1995), completed the Australian Research Council Post-Doctoral Fellowship, James Cook University of Northern Queensland (1996-1997) and was Researcher and Principal Scientist at GNS Science, Lower Hutt New Zealand (1998-2016). Qualified as a professor in Earth Sciences, Naish was Director of the Antarctic Research Centre at Victoria University of Wellington from 2008 until 2017, when he took up a Royal Society of New Zealand James Cook Fellowship. He joined the leadership team of The Antarctic Science Platform in 2019. As of 2023, Naish is a member of the Joint Scientific Committee of the World Climate Research Programme (WCRP) and co-leads an international research programme investigating Instabilities and Thresholds in Antarctica (INSTANT) for the Scientific Committee on Antarctic Research (SCAR).
Research by Naish focuses on past, present and future climate with specific emphasis on how the Antarctic ice sheets respond to climate change and influence global sea-levels. Early work in this area began while he was completing his PhD in 1996 and became interested in a project in Whanganui, New Zealand that was exploring how sedimentary rocks could show the history of two and a half million years of changes in the sea level.Naish coordinated research on the Whanganui Basin in 1995 , 1996 , and 1997 with each of these projects contributing to the understanding of the Plio-Pleistocene boundary by collecting data on shelf deposits of sediment in the Whanganui Basin that showed recurring global changes in sea levels. In September and October of 1999, Naish led a team that drilled deep holes in the Basin with the aim of confirming that "the Wanganui succession is gaining a reputation as one of the most complete shallow marine records of late Neogene sea level and climatic change in the world". Discussing a research project led by Professor Ken Miller, of Rutgers University, with which he was involved in 2012, Naish said that "Whanganui holds one of the world's best geological archives of global sea-level during the warm climate of the Pliocene and is a key data set in this new study...[and]...it is the window into the future and it just so happens the window is mostly open in New Zealand". In the same article, Naish reflected that he had gone "the full circle" having seen the evidence in New Zealand and Whanganui and then seeing the evidence that the ice sheet had actually collapsed.
Naish and a team returned to the Whanganui Basin in 2014 to drill 500 metres into the layers of sediment. The aim was to reduce the uncertainty of a previous estimate that sea levels were 20 metres higher in the Pliocene period - a time when the world had about the same amount of greenhouse gases such as CO2 as in the 21st century and was a few degrees warmer. This was important because understanding historical changes in global sea levels links to Antarctica's ice sheets and their vulnerability to melting.In 2019 Naish worked with Gavin Dunbar of the Antarctic Research Centre and Georgia Grant, a recent Victoria University of Wellington PhD graduate now at GNS Science. They used a new method of analysing marine geological sediment archived from the previous Whanganui Basin research and were able to show that "during the past warm period of the Pliocene about three million years ago, global sea levels regularly fluctuated between 5 to 25 metres". According to Grant, it was concerning because a high percentage of the heat from global warming had gone into the Southern Ocean which surrounds the Antarctic ice sheet, making the sheet vulnerable to widespread and catastrophic collapse from ocean heating. It was noted that the ice sheet had melted in the past when CO2 levels were the same as 2019.
Naish contributed to the guide document setting up The ANDRILL McMurdo Ice Shelf Project (2006). CO2 levels were significantly lower than in the modern era. The project was aiming to date the sediments to identify just when the ice disappeared and link this back to the climate of the time.The prospectus for this project, co-authored by Naish, explained its goal was to gather geological data to determine past ice shelf responses to climate warming by drilling a stratigraphic hole from the Ross Ice Shelf to gather the body of accumulated sediment for analysis and record ocean temperatures. Early in its work in 2006, the project established what had happened to this sediment historically and how in the natural cycles at the time,
In 2007 at the European Geosciences Union General Assembly meeting, Naish reported on the progress of ANDRILL, noting the importance of getting data from sediment close to the Antarctic ice sheets that could provide historical information about how the ice interacts with the global climate system. He said that the drilling in 2006 "had successfully retrieved a 1,285m-long core of rock - the longest core drilled anywhere on the Antarctic margin, and a record of past climate conditions that probably spans some 10 million years into the past".This report noted that the research had discovered single-celled algae (fossil diatoms) under the ocean floor, indicating large areas of the ice shelf had retreated, possibly onto the Antarctic landmass. The research team interpreted this to mean that millions of years ago there were times when the climate was very cold and very hot and it was important to ascertain how this had affected the ice sheet, and could provide information to establish how sensitive the ice was to warming and whether this could lead to the collapse of the West Antarctic Ice Sheet (WAIS). David Harwood, from the University of Nebraska, said that the ANDRILL data was an important point of reference for other research on Antarctica and would situate information into a "chronology that is the best continuous record we have to date". In 2007 Naish also co-authored another summary of the achievements of ANDRILL in the project's first year, confirming that the cores contained rocks with historical evidence of climate variations in Antarctica, enabling predictions to be made about how the iced sheets could respond to global warming. Overseas studies conducted on Russian sediment cores, discussed by Julie Brigham-Grette and Steve Petsch from the University of Massachusetts, Amherst in 2020, confirmed that if the CO2 emission levels were not reduced globally, the fears of some scientists that the Arctic will be completely ice-free within the next two decades will be realised.
By 2009, Naish was confident the ANDRILL data would show that "Antarctica's ice sheets [had] grown and collapsed at least 40 times over the past five million years...[and]...the findings [were] expected to contribute to significant changes in the fifth assessment of the UN's Intergovernmental Panel of Climate Change (IPCC)".
In 2016 he won a Research Fellowship in Physical Science at James Cook University in Australia, to contribute to research entitled: The contribution of the Antarctic ice sheet to past and future sea-level rise and implications for New Zealand.
From 2017, Naish has been Group Co-Leader, Past Antarctic Ice Sheet Dynamics (PAIS) Scientific Committee on Antarctic Research (SCAR), Cambridge, United Kingdom.He explained that the priority of SCAR was to develop research programmes related to environmental change and sustainability and provide "defensible scientific evidence" to the Antarctic Treaty System. This recognition of the importance of a global approach to sustainability was the reason SCAR aimed to work closely with the United Nations Framework Convention on Climate Change (UNFCCC) and provide research studies to the Intergovernmental Panel on Climate Change(IPCC), with two of SCAR's research programmes already having contributed to the IPCC's Fifth Assessment Report.
For the period 2020–2023, as part of The Antarctic Science Platform, Naish was chosen to lead research programmes focussing on the effects of a warming world on the ice-ocean-atmosphere of Antarctica. The project involved drilling projects on the ice sheets and shelves, rock sampling and ocean measurements.
Along with Richard Levy, Naish leads the NZ SeaRise project, a five-year (2018-2023) research programme funded by the Ministry of Business, Innovation and Employment and hosted at Victoria University of Wellington.Naish clarified that the research of NZ SeaRise would result in "maps showing coastline changes, and new information about the frequency of large coastal floods will describe the consequences of sea-level rise for our main coastal cities". When the project presented data in May 2022 that showed the sea levels in New Zealand were rising faster than previously predicted, Naish said he was surprised at how soon parts of Auckland and Wellington would be impacted but that people should not be overwhelmed by the data and there was still time to adapt and make plans to deal with the rise in levels. He did urge however that because parts of Wellington and Auckland were "subsiding at rates of more than 3mm each year...[councils needed to be]... putting in place serious plans for adaptation right now". Speaking to Newsroom Naish explained how this related to the movement of tectonic plates:
Being a New Zealander, we know that the land goes up and the land goes down and we have earthquakes. So we certainly expected that, by the time we put these vertical land movements into the sea level predictions, they would have an effect. But I think we were quite stunned by the magnitude of that effect and how much it really mattered in the very near term, in the coming decades.
Naish noted that sea-level rise depended on climate change initiatives, including limiting global warming to below 2C above pre-industrial levels, and concluded that "the severity with which we will experience sea-level rise, and other impacts of climate change, can be lessened if we do all we can to limit warming by reducing emissions now".
In the 2010 New Year Honours, Naish was awarded the New Zealand Antarctic Medal, for services to Antarctic climate science.For his research on Antarctica's response to climate change over time and the role of melting ice sheets on sea levels, he was awarded The Tinker-Muse Prize for Science and Policy in Antarctica in 2014.
On 3 November 2014, Naish was elected as Fellow of the Royal Society of New Zealand. Identified as one of New Zealand's top researchers and scientific scholars, Naish said:
I'm very humbled to receive this recognition; it is a huge honour as a scientist in New Zealand. It's more than a personal thing—research has and always will be collaborative and this award reflects a whole group both nationally and internationally.
Naish was one of a team of geologists, glaciologists and social scientists that won the 2019 Prime Minister's Science Prizefor their work on the impact of Antarctica's ice sheets melting on global sea levels. Naish was the team leader and another member, Richard Levy from GNS Science and Victoria University of Wellington credited him with "bringing together scientists and experts to ensure the project's success".
In 2002, between 31 January and 7 March when the Antarctica's Larsen B ice shelf collapsed and broke up, Naish warned that the ice shelf of Weddell Sea was imperiled, and if the temperature rose by 3°C, the ice shelves of Antarctica could become thinner.In 2009 there was a threat to sea levels from melting ice when the Wilkins ice shelf in Antarctica was in danger of breaking up. Naish explained that it was the ice sheets and glaciers trapped below the ice shelf that could add new water in the case of the ice shelf melting.
In 2016, prior to a nationwide speaking tour of New Zealand, Naish and James Renwick released a document that listed what they thought were the most important reasons to be concerned about climate change.
As talks began in 2015 for the Paris Agreement, Naish stressed the importance of Antarctica in the issue of climate change because "it held 70 per cent of the worlds freshwater as ice, and if it entirely melted global sea-level would rise sea-levels by 60m".He noted that although Antarctica was protected under the Antarctic Treaty, many people were still unaware of its role in climate change. By 2019 Naish was confident that, based on scientific evidence, if greenhouse gas emissions were not in line with the Paris Agreement target of 2 degrees warming, both the East and West Antarctic ice sheets could be lost.
Naish was invited to speak at the First Antarctic Parliamentarians Assembly in London (2019).Prior to leaving, Naish noted that it was the 60th anniversary of the signing of the Antarctic Treaty and it was timely for parliamentarians and experts to be meeting if the Antarctic continent is to remain a "demilitarized zone to be preserved for scientific research...[and]...don't give up on mitigation, but at the same time, be prepared to adapt to what's coming". Naish's presentation focused on the rise in global sea levels as a result of the loss of Antarctic ice and stressed that the science indicated this was a climate emergency that parliamentarians needed to address urgently. Each speaker was asked for a final message and Naish said [it was] "right to celebrate the success of the Treaty System, but until now it has looked inwards and focused on its own interests, maybe it's now time to look more broadly at the role of Antarctica in these urgent global issues...the science makes it clear that this is, absolutely, an emergency. The people are now listening and time is critical in addressing the biggest challenge of our time: climate change and its impact on humanity". At end of the Assembly, all parliamentarians signed a statement of support for their parliaments to "adopt, where appropriate, additional national legislation contributing to the full and effective implementation of the Antarctic Treaty System".
In June 2023 Naish explained that Earth's physical and economical systems were interconnected and while "designed to reach equilibrium" through sequences of repeating change reactions known as feedback loops, the consequences may destabilize the systems, resulting in change [that] "can be abrupt and irreversible on human timescales if the threshold or tipping point is reached". °C above pre-industrial temperatures" with the Southern Ocean becoming 2 °C warmer, resulting in the loss of over 45% of the sea ice. The resultant polar amplification Naish claimed, could destabilize and melt the Antarctic ice sheet such that "by 2100, 50% of ice shelves will be gone. By 2150, all will have melted". Vulnerability to marine ice sheet and ice cliff instability would be likely to cause an irreversible process of melting, with a possible rise in sea levels of three metres per century, leading Naish to conclude: "These changes highlight the urgency for immediate and deep cuts to emissions. Antarctica has to remain a stable ice-covered continent to avoid the worst impacts of rising seas".In the piece, Naish used one possible sequence of changes and consequences relevant to the effect of global heating on the Antarctica's ice sheets and how this could result in rising sea levels. Based on this model, he predicted that by 2070, without a major reduction in emissions, the climate over Antarctica would "warm by 3
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about 200 miles (320 km) from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of 637,000 square kilometres (246,000 sq mi).
The climate of Antarctica is the coldest on Earth. The continent is also extremely dry, averaging 166 mm (6.5 in) of precipitation per year. Snow rarely melts on most parts of the continent, and, after being compressed, becomes the glacier ice that makes up the ice sheet. Weather fronts rarely penetrate far into the continent, because of the katabatic winds. Most of Antarctica has an ice-cap climate with extremely cold and dry weather.
In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi). The only current ice sheets are in Antarctica and Greenland; during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America.
The Amundsen Sea is an arm of the Southern Ocean off Marie Byrd Land in western Antarctica. It lies between Cape Flying Fish to the east and Cape Dart on Siple Island to the west. Cape Flying Fish marks the boundary between the Amundsen Sea and the Bellingshausen Sea. West of Cape Dart there is no named marginal sea of the Southern Ocean between the Amundsen and Ross Seas. The Norwegian expedition of 1928–1929 under Captain Nils Larsen named the body of water for the Norwegian polar explorer Roald Amundsen while exploring this area in February 1929.
The Antarctic Peninsula, known as O'Higgins Land in Chile and Tierra de San Martín in Argentina, and originally as Graham Land in the United Kingdom and the Palmer Peninsula in the United States, is the northernmost part of mainland Antarctica.
The Western Antarctic Ice Sheet (WAIS) is the segment of the continental ice sheet that covers West Antarctica, the portion of Antarctica on the side of the Transantarctic Mountains that lies in the Western Hemisphere. The WAIS is classified as a marine-based ice sheet, meaning that its bed lies well below sea level and its edges flow into floating ice shelves. The WAIS is bounded by the Ross Ice Shelf, the Ronne Ice Shelf, and outlet glaciers that drain into the Amundsen Sea.
The Larsen Ice Shelf is a long ice shelf in the northwest part of the Weddell Sea, extending along the east coast of the Antarctic Peninsula from Cape Longing to Smith Peninsula. It is named after Captain Carl Anton Larsen, the master of the Norwegian whaling vessel Jason, who sailed along the ice front as far as 68°10' South during December 1893. In finer detail, the Larsen Ice Shelf is a series of shelves that occupy distinct embayments along the coast. From north to south, the segments are called Larsen A, Larsen B, and Larsen C by researchers who work in the area. Further south, Larsen D and the much smaller Larsen E, F and G are also named.
The Antarctic ice sheet is one of the two polar ice caps of Earth. It covers about 98% of the Antarctic continent and is the largest single mass of ice on Earth, with an average thickness of over 2 kilometers. Separate to the Antarctic sea ice it covers an area of almost 14 million square kilometres and contains 26.5 million cubic kilometres of ice. A cubic kilometer of ice weighs approximately 0.92 metric gigatonnes, meaning that the ice sheet weighs about 24,380,000 gigatonnes. It holds approximately 61% of all fresh water on Earth, equivalent to about 58 meters of sea level rise if all the ice were above sea level. In East Antarctica, the ice sheet rests on a major land mass, while in West Antarctica the bed can extend to more than 2,500 m below sea level.
Pine Island Glacier (PIG) is a large ice stream, and the fastest melting glacier in Antarctica, responsible for about 25% of Antarctica's ice loss. The glacier ice streams flow west-northwest along the south side of the Hudson Mountains into Pine Island Bay, Amundsen Sea, Antarctica. It was mapped by the United States Geological Survey (USGS) from surveys and United States Navy (USN) air photos, 1960–66, and named by the Advisory Committee on Antarctic Names (US-ACAN) in association with Pine Island Bay.
Thwaites Glacier is an unusually broad and vast Antarctic glacier located east of Mount Murphy, on the Walgreen Coast of Marie Byrd Land. It was initially sighted by polar researchers in 1940, mapped in 1959–1966 and officially named in 1967, after the late American glaciologist Fredrik T. Thwaites. The glacier flows into Pine Island Bay, part of the Amundsen Sea, at surface speeds which exceed 2 kilometres (1.2 mi) per year near its grounding line. Its fastest-flowing grounded ice is centered between 50 and 100 kilometres east of Mount Murphy. Like many other parts of the cryosphere, it has been adversely affected by climate change, and provides one of the more notable examples of the retreat of glaciers since 1850.
ANDRILL is a scientific drilling project in Antarctica gathering information about past periods of global warming and cooling.
The East Antarctic Ice Sheet (EAIS) is one of two large ice sheets in Antarctica, and the largest on the entire planet. The EAIS lies between 45° west and 168° east longitudinally.
Antarctica is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest continent, being about 40% larger than Europe, and has an area of 14,200,000 km2 (5,500,000 sq mi). Most of Antarctica is covered by the Antarctic ice sheet, with an average thickness of 1.9 km (1.2 mi).
Between 1901 and 2018, the average global sea level rose by 15–25 cm (6–10 in), or an average of 1–2 mm per year. This rate accelerated to 4.62 mm/yr for the decade 2013–2022. Climate change due to human activities is the main cause. Between 1993 and 2018, thermal expansion of water accounted for 42% of sea level rise. Melting temperate glaciers accounted for 21%, with Greenland accounting for 15% and Antarctica 8%. Sea level rise lags changes in the Earth's temperature. So sea level rise will continue to accelerate between now and 2050 in response to warming that is already happening. What happens after that will depend on what happens with human greenhouse gas emissions. Sea level rise may slow down between 2050 and 2100 if there are deep cuts in emissions. It could then reach a little over 30 cm (1 ft) from now by 2100. With high emissions it may accelerate. It could rise by 1 m or even 2 m by then. In the long run, sea level rise would amount to 2–3 m (7–10 ft) over the next 2000 years if warming amounts to 1.5 °C (2.7 °F). It would be 19–22 metres (62–72 ft) if warming peaks at 5 °C (9.0 °F).
Kelly Jemison is an American academic geologist specializing in Antarctic diatoms. She studied at Florida State University, participated in the ANDRILL Project, and in 2011 was awarded the Antarctica Service Medal. She currently works as a Geologist for Bureau of Ocean Energy Management in Anchorage, Alaska.
The Antarctic Research Centre (ARC) is part of the School of Geography, Environment and Earth Sciences at Victoria University of Wellington. Its mission is to research "Antarctic climate history and processes, and their influence on the global climate system. The current director of the Antarctic Research Centre is Associate Professor Robert McKay.
Temperature change due to climate change in Antarctica is not stable over the whole continent. West Antarctica is warming rapidly, while the inland regions are cooled by the winds in Antarctica. Water in the West Antarctic has warmed by 1 °C since year 1955. Further increase in temperature in water and on land will affect the climate, ice mass and life on the continent and have global implications. Present-day greenhouse gas concentrations are higher than ever according to ice cores from Antarctica, which indicates that warming on this continent is not part of a natural cycle and attributable to anthropogenic climate change.
Christina Riesselman is an American paleoceanographer whose research focus is on Southern Ocean response to changing climate.
Richard Levy is a New Zealand glacial stratigrapher and paleoclimatologist with expertise in microfossil analysis. As a principal scientist at GNS Science he has been involved in international and New Zealand environmental research programmes focussing on the evolution of the Earth's climate and building an understanding of the role of greenhouse gases in causing anthropogenic climate changes, in particular those impacting global sea levels. He has had extensive experience in scientific drilling, leading major projects, including the ANtarctic geological DRILLing (ANDRILL) Program in Antarctica. Since 2018, Levy has co-led the government funded NZ SeaRise programme.
Robert Murray McKay is a paleoceanographer who specialises in sedimentology, stratigraphy and palaeoclimatology, specifically gathering geological evidence to study how marine-based portions of the Antarctic ice sheet behave in response to abrupt climate and oceanic change. He has been involved in examination of marine sedimentary records and glacial deposits to show melting and cooling in Antarctica over the past 65 million years and how this has influenced global sea levels and climate. This has helped climate change scientists overcome uncertainty about how the ice sheets will respond to global warming and how this can be managed effectively in the 21st century. He has participated in international projects including ANDRILL and the International Ocean Discovery Program (IODP), led major New Zealand government-funded research teams and has received several awards in recognition of his work. Since 2023 McKay has been a full professor at Victoria University of Wellington and from 2019, director of the Antarctic Research Centre.