Concern over human-driven climate change and the lack of success in constraining greenhouse gas emissions has led to growing interest in marine geoengineering as part of a potential solution. When marine phytoplankton die and sink into the deep-ocean, their carbon is sequestered where it may remain out of contact with the atmosphere for decades to millennia. One of the most prominent among the proposed carbon dioxide reduction interventions is ocean fertilisation, which targets the removal of atmospheric carbon dioxide by the addition of nutrients such as iron, nitrogen or phosphorus compounds to stimulate the growth of marine phytoplankton. The purpose of this Position Analysis is (i) to inform Australian federal and state governments and the broader community about the growing pressure to use the oceans for geoengineering in general and ocean fertilisation specifically; (ii) to provide an update on research concerning ocean fertilisation; and (iii) Identify issues for consideration in science and policy development.
ICE CORES AND CLIMATE
Ice cores are arguably the richest single source of information about the Earth’s climate available to scientists today. Researchers from the ACE CRC and its partner institutions, particularly through the work undertaken at Law Dome in Antarctica, have been involved in landmark ice core research projects that have significantly increased our knowledge of pre-instrumental climate. This Position Analysis explores several recent discoveries in ice core climate science as well as future objectives, with a special focus on Australian-led palaeoclimate initiatives through the ACE CRC.
ANTARCTIC SEA ICE AND CLIMATE CHANGE
The annual expansion and contraction of sea ice in the Antarctic represents one of the biggest natural changes on Earth. At its maximum annual extent in September/October sea ice cover extends about 19 million square kilometres of the ocean around Antarctica – one and half times the size of the continent itself. In the summer sea ice shrinks to around 3 million square kilometres.
SEA LEVEL RISE
Understanding the contributions to present sea-level rise, and their causes, is crucial to projecting what might happen in the future. The purpose of this document is: 1. To update the Australian Government and the community on the latest developments in sea-level rise research, particularly those since 2008 when the ACE CRC produced Briefing: a post-IPCC AR4 update on sea-level rise; 2. To explain the components of sea-level rise and summarise our knowledge of how these could influence sea-level rise in the future; and 3. To inform policymakers, planners and infrastructure developers on the tools available to assist with adaptation to future sea-level rise.
SOUTHERN OCEAN ACIDIFICATION
There is now a clear scientific consensus that the increasing volume and rate of our carbon dioxide (CO2) emissions are causing rapid and unprecedented changes in our oceans. These will have potentially serious impacts within the 21st century, for the sustainability and management of many marine and coastal ecosystems. This report sets the issues in plain language, explaining what we know, what we don’t yet know, what’s at stake and what scientific work is currently being undertaken.
CLIMATE CHANGE AND THE SOUTHERN OCEAN
Given the critical role of the Southern Ocean in the Earth’s climate system, changes in the Southern Ocean have global ramifications. In fact, changes are already under way. The Southern Ocean has warmed and freshened, become more acidic and ocean circulation patterns have changed. Changes in marine ecosystems in the Southern Ocean have been linked to these changes.
CHANGES TO ANTARCTIC SEA ICE
Sea ice extent and thickness – are important indicators of the polar response to climate change. This report explores the latest scientific knowledge on the central role of sea ice in the global climate system, as well as the the uncertainties that exist in current forecasting models.
POLAR ICE SHEETS AND CLIMATE CHANGE: GLOBAL IMPACTS
Sea-level rise, with associated effects such as increased frequency of severe storm surges, will be one of the greatest impacts of a warming world on human societies. Even if global warming stabilises, the ice sheets will continue to add to sea level for many centuries into the future. This report outlines the likely effect of global warming on the polar ice sheets, and the potential impacts of ice sheet change on sea level.
CLIMATE CHANGE, SEA-LEVEL RISE AND EXTREME EVENTS
This position analysis outlines recent developments in the science of sea-level rise and its influence on the effects of extreme events such as high tides and storm surges. It also identifies some of the key issues around the potential impacts of sea-level rise and extreme events and the consequences they will have for Australia and its neighbours.
A POST-IPCC AR4 UPDATE ON SEA LEVEL RISE
In this briefing, we address the science of sea-level rise and briefly mention the potential impacts of sea-level rise. We report recent progress in understanding sea-level rise and also clarify confusion around interpretations of the IPCC sea-level projections.