Day: December 22, 2022

From melting glaciers and shrinking lakes to destroyed harvests and increased health risks, the impacts of climate change are visible and tangible. A particular location’s climate can be described as its average weather conditions over a significant period of time, and climate change refers to shifts in those weather patterns. Warmer temperatures are changing weather patterns and disrupting nature’s equilibrium and our daily lives.

Globally, temperatures have increased to about 1.1 degrees Celsius above pre-industrial levels, and the past seven years have been the warmest on record, according to the World Meteorological Organization (WMO). However, warmer temperatures are just the beginning of the story.

“Climate change is changing the face of our world,” said Oksana Tarasova, Senior Scientific Officer at the WMO. “Through increasing temperatures, sea level rise, increasing intensity of extreme events, climate change impacts our life and property.”

While natural factors, such as volcanic eruptions and plant decomposition, influence the climate, scientists agree that human activity is the main driver of climate change. Burning fossil fuels — namely coal, oil and gas — and clearing land and forests generate emissions of greenhouse gases (GHGs), such as carbon dioxide (CO2) and methane, that trap heat and lead to higher temperatures.

The latest WMO report confirmed that greenhouse gas concentrations reached a record high in 2021. The concentration of carbon dioxide measured 415.7 parts per million (ppm) globally, or about 50 per cent above pre-industrial levels.

“Reducing human impact on climate would mean addressing greenhouse gases emissions,” Tarasova said. “The question is: how can we do it in the most efficient way?”

The answer is in the air, and it is revealed by stable isotopes.

Stable isotopes

Stable isotopes are non-radioactive forms of atoms. Nuclear techniques are used to measure the amount and proportion of isotopes in matter, and this information — the isotopic signature — can be used to determine their source.

In order to address climate change, scientists are studying air samples and using nuclear techniques to determine the source of the problem. “We need to understand the sources, the sinks (which is anything that absorbs more carbon from the atmosphere than it releases) and the isotopic composition, or isotopic signature, of carbon dioxide,” said Manfred Gröning, Head of the IAEA Terrestrial Environmental Radiochemistry Laboratory. “The isotopic composition of carbon dioxide in a sample of air is like an identity card that reveals if it came from a natural or industrial process.”

By identifying the source of emissions, more effective and efficient efforts can be implemented to target the polluters and to reduce GHGs in the atmosphere. “There may be a wildfire in one area, agricultural activities and the deterioration of plants in another area, and then the burning of fossil fuels. All that plays into the complexity of climate change,” Gröning said. “We want to scientifically identify those sources of emissions.”

Reference materials

Climate change has no borders and affects all parts of the planet. A unified approach for global monitoring depends on standardizing isotopic measurements, and this is where the IAEA plays a major role.

“The IAEA has experts not only in isotopic analysis but also in developing reference materials,” said Federica Camin, an IAEA Reference Materials Specialist. Reference materials are physical standards that are used to calibrate laboratory equipment. Since the 1960s, the IAEA has developed and distributed reference materials for laboratories to assist in quality assurance of results using nuclear analytical techniques.

“When measuring mass, the kilogram is the standard of measurement. When measuring GHGs, reference materials provide that standard so that laboratories are aligned on the same measurement scale, independent of location. That’s what you need for a global monitoring system,” Camin said. The IAEA has developed a carbonate standard in the form of a white powder housed in a small vial. “From this powdered solid carbonate, laboratories can produce carbon dioxide gas to calibrate their analytical instruments,” she said.

To improve users’ access to CO2 reference materials, the IAEA is in the process of producing gaseous reference materials that will be easier for laboratories to utilize. “About 40 laboratories in the world are spearheading the measurement of stable isotopes in greenhouse gases in the atmosphere. These labs require standards,” Camin said. “We are developing three new CO2 gas reference materials so that more laboratories can use them, and thus contribute to a high quality dataset of greenhouse gases in the world.” The new reference materials are expected to be distributed in 2024.

Lab support

The accurate measurement of atmospheric GHG concentrations and of their isotope ratios is extremely complicated, Gröning said. These measurements require sufficient laboratory equipment, protocols and human resources to ensure comparable data. Only a few institutions are qualified to measure isotopes for tracking and tracing GHG emissions to their exact source. In 2021, to help close gaps in global measurements, the IAEA and WMO launched their first joint technical cooperation project to help establish capacity for isotope measurements, particularly of methane emissions, across Africa, Asia and the Pacific, Europe, and Latin America and the Caribbean.

“In the next decades, more methane will be released into the atmosphere from the melting permafrost,” Gröning warns. Globally, understanding how the release of methane could develop and how methane is transferred, decayed, or destroyed will help to inform scientists of the processes and measures needed to mitigate climate change. The IAEA is in the process of developing methane gas reference materials.

By developing capacities for using isotopic techniques to monitor measurements, more data can be collected and added to the WMO’s Global Atmospheric Watch. The programme is used to monitor GHG trends in the Earth’s atmosphere. “We need more measurements and higher quality data to understand our outlook in the years and decades to come,” Gröning added. “It will take time, but there is a lot of potential for results,” he said. 

Source: International Atomic Energy Agency

There is more to freshwater resources than meets the eye. While fresh water is visible in the form of rivers, lakes and glaciers, fresh groundwater resources — hidden beneath the Earth — often go unseen.

Groundwater is found in spaces within soil, sand and rock, and is stored in, and moves slowly through, aquifers. It accounts for 99 per cent of Earth’s fresh water, and, according to the United Nations Educational, Scientific and Cultural Organization (UNESCO), nearly half of the world’s urban population depends on it. This dependency on groundwater is expected to grow in light of the effects of climate change.

The volatility of rainfall patterns and the frequency of extreme weather events, as well as the challenges posed by pollution and intensive agriculture, affect the distribution and availability of water resources, explained Yuliya Vystavna, an isotope hydrologist at the IAEA. This is particularly relevant in arid and semi-arid regions of Africa, which experience high rates of evaporation, little rainfall and are largely dependent on groundwater resources. “In order to cope with these challenges and the scarcity of water, we need to have an understanding of water resources and manage them in a sustainable way,” she added.

Uncovering groundwater characteristics

North Africa, home to the Sahara Desert, is one of the driest regions on the planet. Tunisia, located in the northernmost part of the African continent, suffers from variability in rainfall and ranks among those countries with the least water resources in the Mediterranean, said Rim Trabelsi, Director of the Department of Geological Engineering and member of Tunisia’s Laboratory of Radioanalysis and Environment (LARAE) of the National Engineering School of Sfax (ENIS). “That’s why groundwater is really the most reliable resource for the sustainable development of Tunisia, and the population is depending more and more on groundwater supplies.”

The increased use of groundwater has highlighted the need to better understand the links between groundwater recharge and discharge — the movement of water from surface water to groundwater and vice versa. “Groundwater management is increasingly important because of climate variability causing groundwater levels to decline throughout the year, and because of the quality risks posed by nitrate pollution, or salinization by seawater intrusion,” Trabelsi said.

By studying isotopes of water, scientists can provide guidance on how to protect and manage this resource. The amount of naturally occurring stable isotopes of water, and of other substances, is used to reveal the water’s origin, movement, quality and age, as well as to identify sources of contamination. Water age, measured by the concentration of specific isotopes, for example, can range from months to millions of years. The age of groundwater is key to predicting the presence of contaminants, and to understanding how quickly aquifers are replenished.

‘Young’ groundwater can be replenished by surface water from precipitation but can also be affected by pollution and changing climatic conditions, Trabelsi explained, while ‘old’ groundwater, which takes much longer to replenish, is less likely to be contaminated or affected by changes in climate.

Growing analytical capacity

As in many scientific fields, the application of isotope hydrology tools and analysis requires building capacity.

When Hamid Marah first began working in the field of water resource management in Morocco in the 1990s, water samples had to be sent to countries outside of Africa for analysis. There were no laboratories in Africa that had the capability to analyse stable isotope compositions, said Marah, Scientific Director at Morocco’s National Centre for Nuclear Energy, Sciences and Technology (CNESTEN). “Thanks to IAEA support, over the years the capabilities of the continent have been enhanced, and we now have several laboratories in Africa that can analyse isotopes reliably.”

Through the IAEA’s technical cooperation programme and coordinated research projects, isotope hydrology tools are spreading across Africa, enabling scientists to sustainably tap into groundwater resources. Over the past ten years, almost half of the IAEA’s climate change adaptation projects, including water resource management projects, have taken place in Africa. Countries such as Morocco and Tunisia are playing a leading role in the application of isotope techniques across the continent and the Middle East.

Since 2009, LARAE and CNESTEN have been AFRA regional designated centres, and in 2015 CNESTEN became an IAEA Collaborating Centre focusing on water resources assessment and management. AFRA, which stands for the African Regional Co-operative Agreement for Research, Development and Training related to Nuclear Science and Technology, is an intergovernmental agreement established by African countries to strengthen and enlarge the contribution of nuclear science and technology to socio-economic development on the African continent. LARAE and CNESTEN regularly train scientists from across Africa and the Middle East and have carried out thousands of isotope analyses for national hydrological studies and IAEA-supported projects, which aim to address water availability and quality issues related to aquifers and basins.

In a 2020 study, for example, groundwater samples from an aquifer in central-west Tunisia were analysed by LARAE for chemical and isotopic measurements. In recent decades, the expansion and development of irrigated agriculture has depleted surface water resources. The study helped to determine the groundwater’s suitability for drinking and irrigation, and identified sources of salinity variation. The study, which was supported by the IAEA through a coordinated research project, was published in the journal Agriculture, Ecosystems & Environment in June 2021.

There will be an opportunity to learn more about groundwater resources and their role in climate change adaptation and mitigation at the IAEA’s International Symposium on Isotope Hydrology, to be held from 3 to 7 July 2023 in Vienna, Austria. Source: International Atomic Energy Agency

Rwanda’s army “engaged in military operations” against DR Congo’s military in the country’s troubled east, according to a report by a group of independent United Nations experts seen by Agence France-Presse on Thursday.

The experts said there was “substantial evidence” that the Rwandan army directly intervened in Congo’s fight against M23 rebels, and that it had supported the group with weapons, ammunition and uniforms.

A government spokesperson in Kigali denied Rwanda supported the rebels and declined to comment on specific allegations until the findings were formally published.

The Democratic Republic of Congo has repeatedly accused Rwanda of backing the M23.

The militia has captured swaths of territory in the DRC’s restive east since it emerged from dormancy late last year.

Current front lines lie 20 kilometers from Goma, a commercial hub of more than 1 million people.

Rwanda has repeatedly denied it supports the rebels, but the United States and France, among other Western countries, have agreed with the DRC’s assessment.

According to the U.N. experts’ report, Rwanda’s military intervened to reinforce the M23 as well as to combat the Democratic Forces for the Liberation of Rwanda (FDLR) — a descendant of Rwandan Hutu extremist groups that carried out the 1994 Tutsi genocide in Rwanda.

Rwanda provided troop reinforcements to the M23 “for specific operations, in particular when these were aimed at seizing strategic towns and areas,” the report added.

Rwandan troops also led joint attacks with M23 fighters against Congolese positions in May, according to the report.

The 236-page document for the U.N. Security Council is expected to be published in the coming days.

Diplomatic crisis

Alain Mukuralinda, Rwanda’s deputy government spokesman, said Kigali had not seen the substance of the report or the evidence it was based upon.

“Today, as long as we have not seen the material evidence, as long as we have not examined this so-called evidence, it is difficult to take a position,” he told AFP.

But he added: “We do not support the M23, we do not need it.”

A Tutsi-led militia, the M23 first came to international prominence when it captured Goma in 2012, before being driven out and going to ground the following year.

But it re-emerged in late 2021 after the rebels claimed the DRC had ignored a promise to integrate them into the army and has since made significant advances.

A watershed moment came in June when M23 fighters captured the strategic town of Bunagana on the Ugandan border.

A fresh offensive in late October saw the M23 capture swaths of territory in North Kivu, displacing hundreds of thousands of people.

The rebels’ battlefield successes have sent relations between the DRC and neighboring Rwanda into a nosedive.

Several diplomatic initiatives have been launched in a bid to ease tensions, with the seven-nation East African Community (EAC) also deciding to deploy a military force to eastern DRC.

Talks between the DRC and Rwanda in the Angolan capital Luanda led to a truce agreement on November 23.

Under the deal, the M23 was to lay down arms and pull back from occupied territories.

But clashes with M23 continued.

Kinshasa subsequently accused the M23 of massacring civilians in the village of Kishishe.

A preliminary U.N. probe found that the M23 killed at least 131 civilians in the area.

On Wednesday, Rwanda said allegations of a massacre were a “fabrication.” It said the incident involved clashes between the M23 and Kinshasa-allied militias.

Militia shift

Armed groups, of which there are more than 120 in eastern DRC, have taken the fight to the M23 in recent weeks.

According to the U.N. experts’ report, the M23’s resurgence caused local militias to “shift alliances,” creating “new dynamics” with the Congolese military.

The experts cited evidence that Congolese troops had fought alongside armed groups in their struggle against the M23.

The U.N. experts recommended that the DRC “take all measures” to prevent cooperation between the Congolese military and armed groups.

They likewise urged Congo’s neighboring states to “prevent the provision of support” to armed groups within the vast nation of 90 million people.

Asked about the report, the U.S. State Department voiced concern and called on all nations to respect “territorial integrity.”

“Entry of foreign forces into the DRC must be done transparently with the consent of, and in coordination with, the DRC, and must be pre-notified to the Security Council in line with existing U.N. sanctions resolutions for the DRC,” a State Department spokesperson said.

The United States has repeatedly said that allegations of Rwandan support to the M23 rebels were credible.

Source: Voice of America