United in Science report: Climate Change has not stopped for COVID19

By SalM on September 9, 2020 in News Articles

New York/Geneva – Climate change has not stopped for COVID19. Greenhouse gas concentrations in the atmosphere are at record levels and continue to increase. Emissions are heading in the direction of pre-pandemic levels following a temporary decline caused by the lockdown and economic slowdown. The world is set to see its warmest five years on record – in a trend which is likely to continue – and is not on track to meet agreed targets to keep global temperature increase well below 2 °C or at 1.5 °C above pre-industrial levels.

This is according to a new multi-agency report from leading science organizations, United in Science 2020. It highlights the increasing and irreversible impacts of climate change, which affects glaciers, oceans, nature, economies and human living conditions and is often felt through water-related hazards like drought or flooding. It also documents how COVID-19 has impeded our ability to monitor these changes through the global observing system.

“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,” said UN Secretary-General António Guterres in a foreword.

“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,” said Mr Guterres, who will present the report on 9 September. “We need science, solidarity and solutions.”

The United in Science 2020 report, the second in a series, is coordinated by the World Meteorological Organization (WMO), with input from the Global Carbon Project, the Intergovernmental Panel on Climate Change, the Intergovernmental Oceanographic Commission of UNESCO, the UN Environment Programme and the UK Met Office. It presents the very latest scientific data and findings related to climate change to inform global policy and action.

“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,” said WMO Secretary-General, Professor Petteri Taalas.

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 COconcentrations 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 COin 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)

COemissions 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 COemissions 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 COemissions 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 COand 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 COemissions 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 taken from World Meteorological Organization’s website. Follow the link below to the original article

https://public.wmo.int/en/media/press-release/united-science-report-climate-change-has-not-stopped-covid19

The Spread and Impact of Marine Structures

By SalM on September 9, 2020 in News Articles

More than 32,000 square kilometres of the world’s marine environment has been modified by human construction and this is likely to reach nearly 40,000 by 2028, according to a new global assessment.

When flow-on effects in surrounding areas are included, the footprint is actually two million square kilometres, or more than 0.5% of the total marine area. Development mostly occurs near coasts, which are the most biodiverse and biologically productive environments.

The area directly affected is greater than the global area of some natural marine habitats, such as mangrove forests and seagrass beds, the researchers write in a paper in the journal Nature Sustainability.

And just to underline the complexity of the problem, some of the modification is caused by initiatives designed to help the environment, such as wind farms.

“The proliferation of marine built structures shown here provides a suite of ecological, social and economic benefits – for example, the expansion of renewable sources of energy in the oceans can minimise greenhouse gas emissions,” the authors write.

“In addition, energy extraction infrastructure may sometimes serve to benefit sensitive habitats due to the fishing exclusion zones set up around them and even act as focal points for restoration activities.

“Nevertheless, all marine construction replaces natural habitats and can modify environmental conditions critical to habitat persistence at regional scales.”

The research was led by Ana Bugnot from the Sydney Institute of Marine Science and brought together scientists from Australia, Italy, the US and the UK.

They gathered data and made calculations to estimate the physical footprint and area of seascape modification around marine construction as of 2018, including future trends.

This included 11 categories of activity: gas and oil rigs, subsea pipelines, wind farms, wave and tidal farms, telecommunication cables, aquaculture, commercial ports, tunnels and bridges, breakwaters, recreational marinas, and artificial reefs.

“The numbers are alarming,” Bugnot says. “For example, infrastructure for power and aquaculture, including cables and tunnels, is projected to increase by 50 to 70% by 2028, yet this is an underestimate. There is a dearth of information on ocean development, due to poor regulation of this in many parts of the world.”

This is not a new thing, of course. As the paper acknowledges, humans have been building marine infrastructure to support marine traffic for 4000 years.

But things have “ramped up” since the middle of last century, Bugot says, with both positive and negative results.

“For example, while artificial reefs have been used as ‘sacrificial habitat’ to drive tourism and deter fishing, this infrastructure can also impact sensitive natural habitats like seagrasses, mudflats and saltmarshes, consequently affecting water quality.”

Land reclamation is an emerging trend, with the researchers identifying 479 human-made islands in marine environments worldwide, with some now moving into deeper waters up to 500 kilometres offshore.

Others are built in groups, including The World (United Arab Emirates, 300 islands) and the Fortress Islands (Russia, 19 islands).

“Ongoing demands for space to accommodate an increasing coastal population and the need for ‘designer islands’ to host climate refugees means that land reclamation will continue to spread and occupy a substantial extension of the marine environment,with many associated impacts,” the report says.

The researchers say their study is the first to quantify the extent of human impact.

Because of the difficulty of accurately mapping structures, to date “the most complete assessments of anthropogenic impacts on the oceans and ocean health have relied upon proxies for marine construction, such as human population density, mariculture production and night light intensity from oil and gas platforms”, they write.


This article has been taken from the Cosmos Magazine webpage. Follow the link below to the original article

https://cosmosmagazine.com/earth/sustainability/the-growth-and-impact-of-marine-structures/