‘We must trigger social tipping points’

September 11, 2022 / activist360

The risk of dangerous, cascading tipping points in natural systems escalates above 1.5°C of global warming, states a recent study.

By Yasmin Dahnoun, Ecologist (Creative Commons 4.0).

Multiple climate tipping points could be triggered if global temperature rises beyond 1.5°C above pre-industrial levels, according to a major new analysis published in the journal Science.

Even at current levels of global heating, the world is already at risk of triggering five dangerous climate tipping points, and risks increase with each tenth of a degree of further warming.

An international research team synthesized evidence for tipping points, their temperature thresholds, timescales, and impacts from a comprehensive review of over 200 papers published since 2008 when climate tipping points were first rigorously defined. They have increased the list of potential tipping points from nine to sixteen.

Die-off

The research concludes that we are already in the danger zone for five climate tipping points: melting of the Greenland and West Antarctic ice sheets, widespread abrupt permafrost thaw, the collapse of convection in the Labrador Sea, and massive die-off of tropical coral reefs.

The paper was published ahead of a major conference, Tipping Points: from climate crisis to positive transformation, at the University of Exeter, which will take place next week.

Four of these move from “possible” to “likely” at 1.5°C global warming, with five more becoming possible around this level of heating.

David Armstrong McKay, from Stockholm Resilience Centre, University of Exeter, and the Earth Commission, was the lead author of the report. He said: “We can see signs of destabilization already in parts of the West Antarctic and Greenland ice sheets, in permafrost regions, the Amazon rainforest, and potentially the Atlantic overturning circulation as well.

“The world is already at risk of some tipping points. As global temperatures rise further, more tipping points become possible. The chance of crossing tipping points can be reduced by rapidly cutting greenhouse gas emissions, starting immediately.”

Safe

The Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), stated that risks of triggering climate tipping points become high by around 2°C above preindustrial temperatures and very high by 2.5-4°C.

The new analysis indicates that earth may have already left a “safe” climate state when temperatures exceeded approximately 1°C above preindustrial temperatures.

A conclusion of the research is therefore that even the United Nations’ Paris Agreement goal to avoid dangerous climate change by limiting warming to well below 2°C and preferably 1.5°C is not fully safe.

However, the study provides strong scientific support for the Paris Agreement and associated efforts to limit global warming to 1.5°C, as while some tipping points are possible or likely at this temperature level, the risk escalates beyond this point.

Liveable

To have a 50 percent chance of achieving 1.5°C and thus limiting tipping point risks, global greenhouse gas emissions must be cut by half by 2030, reaching net zero by 2050.

Co-author Johan Rockström, the co-chair of the Earth Commission and director of the Potsdam Institute for Climate Impact Research, said: “The world is heading towards 2-3°C of global warming.

“This sets earth on course to cross multiple dangerous tipping points that will be disastrous for people across the world.

“To maintain liveable conditions on earth, protect people from rising extremes, and enable stable societies, we must do everything possible to prevent crossing tipping points. Every tenth of a degree counts.”

Decarbonising

Tim Lenton, director of the Global Systems Institute at the University of Exeter and a member of the Earth Commission, was a co-author of the report. He said: “Since I first assessed climate tipping points in 2008, the list has grown and our assessment of the risk they pose has increased dramatically.

“Our new work provides compelling evidence that the world must radically accelerate decarbonizing the economy to limit the risk of crossing climate tipping points.

“To achieve that, we now need to trigger positive social tipping points that accelerate the transformation to a clean-energy future.

“We may also have to adapt to cope with climate tipping points that we fail to avoid, and support those who could suffer uninsurable losses and damages.”

Collapse

Scouring paleoclimate data, current observations, and the outputs from climate models, the international team concluded that 16 major biophysical systems involved in regulating the earth’s climate (so-called “tipping elements”) have the potential to cross tipping points where change becomes self-sustaining.

That means even if the temperature stops rising, once the ice sheet, ocean, or rainforest has passed a tipping point it will carry on changing to a new state.

How long the transition takes varies from decades to thousands of years depending on the system.

For example, ecosystems and atmospheric circulation patterns can change quickly, while ice sheet collapse is slower but leads to an unavoidable sea-level rise of several meters.

The researchers categorized the tipping elements into nine systems that affect the entire earth system, such as Antarctica and the Amazon rainforest, and a further seven systems that if tipped would have profound regional consequences.

Interlinked

The latter include the West African monsoon and the death of most coral reefs around the equator.

Several new tipping elements such as Labrador Sea convection and East Antarctic subglacial basins have been added compared to the 2008 assessment, while Arctic summer sea ice and the El Niño Southern Oscillation (ENSO) have been removed for lack of evidence of tipping dynamics.

Co-author Ricarda Winkelmann, a researcher at the Potsdam Institute for Climate Impact Research and a member of the Earth Commission, said: “Importantly, many tipping elements in the earth system are interlinked, making cascading tipping points a serious additional concern.

“In fact, interactions can lower the critical temperature thresholds beyond which individual tipping elements begin destabilizing in the long run.”

Preserving Cultural and Historic Treasures in a Changing Climate May Mean Transforming Them

November 16, 2020 / activist360 / Leave a comment

By Erin Seekamp, Professor of Parks, Recreation and Tourism Management, North Carolina State University

With global travel curtailed during the COVID-19 pandemic, many people are finding comfort in planning future trips. But imagine that you finally arrive in Venice and the “floating city” is flooded. Would you stay anyway, walking through St. Mark’s Square on makeshift catwalks or elevated wooden passages – even if you couldn’t enter the Basilica or the Doge’s Palace? Or would you leave and hope to visit sometime in the future?

The United Nations Intergovernmental Panel on Climate Change recently reported that over the next 30 years flooding in Venice will increase. With the Adriatic Sea rising a few millimeters each year, severe flooding that once happened every 100 years is predicted to happen every six years by 2050, and every five months by 2100.

Venice is just one example of the challenges of preserving iconic landmarks that are threatened by the effects of climate change, such as rising seas and recurrent, intensifying droughts, storms and wildfires. In my research as a social scientist, I help heritage managers make tough decisions prioritizing which sites to save when funds, time or both are limited.

That includes planning for threatened World Heritage sites designated as cultural or natural treasures by the United Nations Educational, Scientific and Cultural Organization. Many U.S. national parks are also at risk. And as I see it, success will require new thinking about what preservation means.

Cultural heritage sites threatened by climate change include cities, towns and national parks.

Ways of adapting

Across the globe, innumerable cultural sites face storm-related flooding, erosion and inundation from rising seas. They include many in the U.S., such as Jamestown Island in Virginia, New York’s Statue of Liberty and Charleston, South Carolina’s Historic District.

Experts in cultural preservation worldwide agree that it is impossible to protect all of these places forever. Many would require constant restoration. Others will need defenses like sea walls and flood gates – but those defenses might not be effective for long.

Some sites could be protected in ways that visibly alter them – for example, elevating or moving buildings, or allowing them to be damaged or removed from the landscape. Such steps go beyond restoration, which can conflict with mandates to preserve sites and structures in perpetuity.

Damage from Hurricane Sandy in 2012 shut down New York’s Statue of Liberty and the Ellis Island immigration museum for months.

Saving historic North Carolina buildings

An early test of this approach occurred in 1999, when relentless erosion of the North Carolina shoreline forced the National Park Service to move the Cape Hatteras Lighthouse and Keeper’s Quarters about a half-mile inland. Relocating these mid-19th-century structures cost $US11.8 million and sparked debate about how to deal with other imperiled historic buildings.

In 2015, managers at North Carolina’s Cape Lookout National Seashore realized that buildings in Portsmouth Village and Cape Lookout Village, two maritime historic districts on barrier islands, were endangered by storm-related flooding and rising seas. Portsmouth Village, which dates to 1753, served as a thriving port town during colonial settlement, while Cape Lookout Village provided navigational support with construction of a lighthouse in 1812 that was replaced in 1859.

These buildings are listed on the National Register of Historic Places, which requires managers to preserve them in perpetuity. But officials were uncertain about which historic buildings to save first. They also had to identify a strategy, such as moving or even removing buildings, that would maximize the significance preserved across the park’s landscape.

I developed a process to quantify the relative significance of historic buildings to help them. Our team then created a planning tool to help National Park Service managers make cost-effective decisions. Our model compiles data on each building’s significance and vulnerability. It evaluates adaptation costs, such as elevating or relocating buildings, given available funding, and charts possible strategies over a 30-year period.

Photo of Cape Hatters Light and path to new site. — *In 1999 the National Park Service moved the historic Cape Hatteras Lighthouse 2,900 feet inland (new site at lower right in photo) to protect it from shoreline erosion. Mike Booher/NPS*

When we tested the model on 17 flood-prone Cape Lookout buildings, we found that the best strategies were elevating them in place or moving them to higher ground and then elevating them. However, interviews with local people revealed that changing the location or the look of these buildings upset some former residents and their descendants.

Many people we talked to held deep connections to these places that were part of their personal, family and community identities. Surprisingly, some said they would rather lose some of these buildings than alter them. Other stakeholders – including members of partner organizations and park visitors – had different opinions on what should be done.

After Hurricane Dorian severely damaged Portsmouth Village in 2019, park managers made the hard decision to dismantle and remove some of the buildings while restoring others. But an important question remains: What should be done at other highly vulnerable locations?

Climate-challenged World Heritage sites

These findings inspired me to explore global, people-centered approaches to preservation and the international policies governing them.

Climate change threatens many World Heritage sites. Some are archaeological sites, like Peru’s Chan Chan, the largest adobe city on Earth, and the ancestral Pueblo cliff dwellings in Colorado’s Mesa Verde National Park. Entire cities – including Venice – and historic buildings such as Australia’s Sydney Opera House are also in harm’s way.

Current policy recommendations focus on restoration or defenses, and oppose physical change. In fact, the only process that exists is to add sites undergoing physical change to the List of World Heritage Sites in Danger. However, adding a site to the “danger” list is politically undesirable because it can generate bad press, reduce tourism revenue and deter funders from supporting rescue efforts.

The need to transform

My research calls for a more proactive approach, including preemptive efforts to prevent damage. I see a need for a new category: “World Heritage Sites in Climatic Transformation.”

This approach draws on the ecological concept of resilience, which is essentially the ability to survive by changing and adapting. It would allow managers to repair, adapt or even transform vulnerable places. This new classification would place communities at the center of the planning process and create a searchable database of climate impacts and interventions.

Transforming heritage sites may be controversial, but the clock is ticking. Researching, designing and constructing defenses takes time. For example, floodgates installed to protect Venice are being tested a decade later than planned.

In my view, saving cultural and historic sites from climate change will require a new approach to heritage preservation that includes transformation. Now is the time to think creatively, with input from people whose heritages are represented in these places, to discover new pathways to protecting them.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

United in Science 2020

September 14, 2020 / activist360 / Leave a comment

A multi-organization high-level compilation of the latest climate science information

According to a new multi-agency report from leading science organizations, United in Science 2020:

2016-2020 is set to be the warmest 5-year period on record
Lockdown related fall in emissions will not reduce CO₂ concentrations
Global fossil CO₂ emissions rose 62% 1990-2019
Consumption patterns must change to support climate action
Climate change impacts cascade from mountain peaks to ocean depths
Glacier and snowmelt threatens water supplies for billions
Droughts and floods produce the most impacts
Sea level rise is accelerating due to polar ice melt.

United in Science 2020 Key Messages — *United in Science 2020: Key Messages*

This has been an unprecedented year for people and planet. The COVID-19 pandemic has disrupted lives worldwide. At the same time, the heating of our planet and climate disruption has continued apace.
Never before has it been so clear that we need long-term, inclusive, clean transitions to tackle the climate crisis and achieve sustainable development. We must turn the recovery from the pandemic into a real opportunity to build a better future.
We need science, solidarity and solutions.”
—António Guterres, United Nations Secretary-General

Greenhouse gas concentrations – which are already at their highest levels in 3 million years – have continued to rise. Meanwhile, large swathes of Siberia have seen a prolonged and remarkable heatwave during the first half of 2020, which would have been very unlikely without anthropogenic climate change. And now 2016–2020 is set to be the warmest five-year period on record. This report shows that whilst many aspects of our lives have been disrupted in 2020, climate change has continued unabated.”
—Professor Petteri Taalas, WMO Secretary-General

Cover Image for United in Science 2020 — *United in Science 2020*

Key Findings

Greenhouse Gas Concentrations in the Atmosphere (World Meteorological Organization)

Atmospheric CO₂ concentrations showed no signs of peaking and have continued to increase to new records. Benchmark stations in the WMO Global Atmosphere Watch (GAW) network reported CO₂concentrations above 410 parts per million (ppm) during the first half of 2020, with Mauna Loa (Hawaii) and Cape Grim (Tasmania) at 414.38 ppm and 410.04 ppm, respectively, in July 2020, up from 411.74 ppm and 407.83 ppm in July 2019.

Reductions in emissions of CO₂in 2020 will only slightly impact the rate of increase in the atmospheric concentrations, which are the result of past and current emissions, as well as the very long lifetime of CO₂. Sustained reductions in emissions to net zero are necessary to stabilize climate change.

Global Fossil CO₂ emissions (Global Carbon Project)

CO₂emissions in 2020 will fall by an estimated 4% to 7% in 2020 due to COVID-19 confinement policies. The exact decline will depend on the continued trajectory of the pandemic and government responses to address it.

During peak lockdown in early April 2020, the daily global fossil CO₂emissions dropped by an unprecedented 17% compared to 2019. Even so, emissions were still equivalent to 2006 levels, highlighting both the steep growth over the past 15 years and the continued dependence on fossil sources for energy.

By early June 2020, global daily fossil CO₂emissions had mostly returned to within 5% (1%–8% range) below 2019 levels, which reached a new record of 36.7 Gigatonnes (Gt) last year, 62% higher than at the start of climate change negotiations in 1990.

Global methane emissions from human activities have continued to increase over the past decade. Current emissions of both CO₂and methane are not compatible with emissions pathways consistent with the targets of the Paris Agreement.

Emissions Gap (UN Environment Programme)

Transformational action can no longer be postponed if the Paris Agreement targets are to be met.

The Emissions Gap Report 2019 showed that the cuts in global emissions required per year from 2020 to 2030 are close to 3% for a 2 °C target and more than 7% per year on average for the 1.5 °C goal of the Paris Agreement.

The Emissions Gap in 2030 is estimated at 12-15 Gigatonnes (Gt) CO₂e to limit global warming to below 2 °C. For the 1.5 ° C goal, the gap is estimated at 29-32 Gt CO₂e, roughly equivalent to the combined emissions of the six largest emitters.

It is still possible to bridge the emissions gap, but this will require urgent and concerted action by all countries and across all sectors. A substantial part of the short-term potential can be realized through scaling up existing, well-proven policies, for instance on renewables and energy efficiency, low carbon transportation means and a phase out of coal.

Looking beyond the 2030 timeframe, new technological solutions and gradual change in consumption patterns are needed at all levels. Both technically and economically feasible solutions already exist.

State of Global Climate (WMO and UK’s Met Office)

The average global temperature for 2016–2020 is expected to be the warmest on record, about 1.1 °C above 1850-1900, a reference period for temperature change since pre-industrial times and 0.24°C warmer than the global average temperature for 2011-2015.

In the five-year period 2020–2024, the chance of at least one year exceeding 1.5 °C above pre-industrial levels is 24%, with a very small chance (3%) of the five-year mean exceeding this level. It is likely (~70% chance) that one or more months during the next five years will be at least 1.5 °C warmer than pre-industrial levels.

In every year between 2016 and 2020, Arctic sea ice extent has been below average. 2016–2019 recorded a greater glacier mass loss than all other past five-year periods since 1950. The rate of global mean sea-level rise increased between 2011–2015 and 2016–2020.

Major impacts have been caused by extreme weather and climate events. A clear fingerprint of human-induced climate change has been identified on many of these extreme events.

The Ocean and Cryosphere in a Changing Climate (Intergovernmental Panel on Climate Change)

Human-induced climate change is affecting life-sustaining systems, from the top of the mountains to the depths of the oceans, leading to accelerating sea-level rise, with cascading effects for ecosystems and human security.

This increasingly challenges adaptation and integrated risk management responses.

Ice sheets and glaciers worldwide have lost mass. Between 1979 and 2018, Arctic sea-ice extent has decreased for all months of the year. Increasing wildfire and abrupt permafrost thaw, as well as changes in Arctic and mountain hydrology, have altered the frequency and intensity of ecosystem disturbances.

The global ocean has warmed unabated since 1970 and has taken up more than 90% of the excess heat in the climate system. Since 1993 the rate of ocean warming, and thus heat uptake has more than doubled. Marine heatwaves have doubled in frequency and have become longer-lasting, more intense and more extensive, resulting in large-scale coral bleaching events. The ocean has absorbed between 20% to 30% of total anthropogenic CO₂emissions since the 1980s causing further ocean acidification.

Since about 1950 many marine species have undergone shifts in geographical range and seasonal activities in response to ocean warming, sea-ice change and oxygen loss.

Global mean sea-level is rising, with acceleration in recent decades due to increasing rates of ice loss from the Greenland and Antarctic ice sheets, as well as continued glacier mass loss and ocean thermal expansion. The rate of global mean sea-level rise for 2006–2015 of 3.6 ±0.5 mm/yr is unprecedented over the last century

Climate and Water Resources (WMO)

Climate change impacts are most felt through changing hydrological conditions including changes in snow and ice dynamics.

By 2050, the number of people at risk of floods will increase from its current level of 1.2 billion to 1.6 billion. In the early to mid-2010s, 1.9 billion people, or 27% of the global population, lived in potential severely water-scarce areas. In 2050, this number will increase to 2.7 to 3.2 billion people.

As of 2019, 12% of the world population drinks water from unimproved and unsafe sources. More than 30% of the world population, or 2.4 billion people, live without any form of sanitation.

Climate change is projected to increase the number of water-stressed regions and exacerbate shortages in already water-stressed regions.

The cryosphere is an important source of freshwater in mountains and their downstream regions. There is high confidence that annual runoff from glaciers will reach peak globally at the latest by the end of the 21st century. After that, glacier runoff is projected to decline globally with implications for water storage.

It is estimated that Central Europe and Caucasus have reached peak water now, and that the Tibetan Plateau region will reach peak water between 2030 and 2050. As runoff from snow cover, permafrost and glaciers in this region provides up to 45% of the total river flow, the flow decrease would affect water availability for 1.7 billion people.

Earth System Observations during COVID-19 (Intergovernmental Oceanographic Commission of UNESCO and WMO)

The COVID-19 pandemic has produced significant impacts on the global observing systems, which in turn have affected the quality of forecasts and other weather, climate and ocean-related services.

The reduction of aircraft-based observations by an average of 75% to 80% in March and April degraded the forecast skills of weather models. Since June, there has been only a slight recovery. Observations at manually operated weather stations, especially in Africa and South America, have also been badly disrupted.

For hydrological observations like river discharge, the situation is similar to that of atmospheric in situ measurements. Automated systems continue to deliver data whereas gauging stations that depend on manual reading are affected.

In March 2020, nearly all oceanographic research vessels were recalled to home ports. Commercial ships have been unable to contribute vital ocean and weather observations, and ocean buoys and other systems could not be maintained. Four full-depth ocean surveys of variables such as carbon, temperature, salinity, and water alkalinity, completed only once per decade, have been cancelled. Surface carbon measurements from ships, which tell us about the evolution of greenhouse gases, also effectively ceased.

The impacts on climate change monitoring are long-term. They are likely to prevent or restrict measurement campaigns for the mass balance of glaciers or the thickness of permafrost, usually conducted at the end of the thawing period. The overall disruption of observations will introduce gaps in the historical time series of Essential Climate Variables needed to monitor climate variability and change and associated impacts.

This report has been compiled by the World Meteorological Organization (WMO) under the direction of the United Nations Secretary-General to bring together the latest climate science related updates from a group of key global partner organizations – WMO, Global Carbon Project (GCP), UNESCO Intergovernmental Oceanographic Commission (UNESCO-IOC), Intergovernmental Panel on Climate Change (IPCC), UN Environment Programme (UNEP) and the Met Office. The content of each chapter is attributable to each respective organization.