Nuclear and isotopic techniques can help study terrestrial and aquatic systems and monitor emissions of greenhouse gases such as carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4), with the aim of assessing the effects of climate change on the environment.
Isotopic techniques allow data to be collected to identify, monitor and manage the sources of greenhouse gas emissions and thus understand how they relate to changes in the land, oceans, and the atmosphere as a whole.
The atoms of each chemical element have a characteristic number of protons, neutrons, and electrons. Atoms with the same number of protons but different numbers of neutrons are called isotopes, and although they have virtually the same chemical properties as the original element, their mass and physical properties are different.
A distinction can be made between stable isotopes that do not emit radiation and unstable, radioactive isotopes that do emit radiation.
Various nuclear techniques to measure the quantities and ratios of isotopes and to trace their origin, history, sources, and interactions in the environment.
What are the applications? Some of them are outlined below:
Reducing emissions in agriculture
Some 25% of greenhouse gas emissions originate from agriculture, for example, when livestock and chemical fertilizers release methane and nitrous oxide, a gas that contributes 300 times more to global warming than carbon dioxide and, in excess, can pollute land and freshwater.
Isotopes and nuclear techniques can help determine the amount of fertilizer absorbed by plants and thus reduce the amount of fertilizer applied and the volume of nitrous oxide emitted.
Strengthening crop production
Climate change has led to extremely dry conditions in many countries, so it is important to understand how drought is affecting crop growth under these new circumstances.
Isotopes can be used to assess the state and movement of water in the soil and to find cheaper and more effective methods of supplying water to crops while saving this precious resource.
In addition, gamma and X-ray irradiation, which accelerate the natural process of genetic modification, is used in mutation induction breeding to develop new crop varieties that are resistant or tolerant to drought, salinity, disease, and pests. Seeds and other plant materials are treated to induce genetic modifications similar to spontaneous mutations, resulting in improved high-yielding varieties and crops better adapted to changes in climate.
Study of the oceans
The ocean absorbs 25% of the carbon dioxide released into the atmosphere, allowing 50 times more carbon dioxide to be stored in the ocean than in the atmosphere. This leads to the acidificación de los oceános, which can affect or even destroy marine organisms.
Nuclear and isotopic techniques make it possible to assess the ocean's capacity to store carbon, the impact of acidification on marine organisms, the evolution of ocean acidity and the consequences for future climate scenarios, and to understand the carbon cycle, including the sources and fate of organic matter.
Understanding water reserves
Climate change affects both global rainfall sources and the distribution of rainfall, and this influences river flow and groundwater recharge.
Isotope hydrology is used to understand how groundwater aquifers are recharged and how vulnerable they may be to climate change. This data helps to protect and conserve groundwater systems. It also examines the isotopic composition of hydrogen and oxygen in water, and as this is unique to the time and location of the rainfall from which it originates, this technique allows the traceability of that element and thus the protection of its source.
Other isotopes are used to determine the age of water found in different aquifer systems so that scientists can discern how best to manage water supplies to ensure their long-term sustainability.