Ocean currents, insects and land conservation: how science tackles climate change

Weather and greenhouse gas emissions conspire against scientists' efforts to curb global warming. However, science does not stop its progress and seeks not only to analyze what the consequences of this situation are, but also how it can be mitigated. They even evaluate and develop programs that will allow forecasts to be made so that individual countries can act accordingly. On the occasion of International Mother Earth Day, here is a small analysis of what science does to address these problems.

Ocean currents participate not only in the “cooling” of the planet, but also capture carbon dioxide. Insects are essential for the pollination of different crops and the conservation of different ecosystems. While knowing where to urbanize and what land to choose to convert into reserves, are all ingredients that can slow global warming and consequent climate change. The experts not only marked the situation but, in addition, many of them listed the solutions or, directly, sought to address the problem with a proposal.

Ocean currents: acceleration and a latent danger

The role of ocean currents is paramount. They transport the nutrients needed by the various organisms that inhabit their waters, as well as removing carbon and heat from the atmosphere, thus preventing the planet from suffering from excessive global warming. However, global warming could alter its entire functioning.

According to a group of scientists from the Scripps Institute of Oceanography in San Diego, when the planet's temperature rises, surface ocean circulations change, causing them to become faster and thinner. “We were surprised to see surface currents accelerate in more than three-quarters of the world's oceans when we warm the ocean's surface,” said Qihua Peng, lead author of the study that was published in the journal Science Advances.

To find out what happens when the temperature of the ocean surface warms up, scientists used a global ocean model. As they were able to determine in the simulation they carried out, when the upper layers of water are heated, they become lighter. In this way, a difference in density develops between the warm and the cold layer, which is located below it. This causes the hottest layer to accelerate its speed, a situation that would occur in three quarters of the world's oceans.

As the speed of the surface ocean currents (known as turns) rise, the cold layers below suffer a slowdown. The result of this situation is an increased presence of greenhouse gases in the atmosphere. It is worth noting that currents or turns are limited by the continents themselves, except for the Southern Ocean in Antarctica, where westerly winds cause the Antarctic Circumpolar Current to become the largest in the world (in terms of volume).

This same group of scientists had detected, last year, that the Antarctic Circumpolar Current was accelerating. “This acceleration is exactly what our model predicts as the climate warms,” said Scripps Oceanography climate modeler Shang-Ping Xie. After this prediction, which became a reality today, scientists seek to stop the development of this, it only remains for States to get down to work and avoid a chain reaction.

Endangered insects: crops and food at risk

Each insect plays a fundamental role within the great ecosystem that is planet earth. Some break down dead material, others help keep other insects under control that would otherwise become pests. While, among the most important, are those who collaborate by pollinating food crops and flowers. However, recent studies have indicated that their population is in decline, which could result in a loss of insect biodiversity and their vital ecological functions would be put in check, putting human livelihoods and food security at risk.

Some of the evidence that has already been recorded are: widespread pollinator losses in Great Britain, a 30-50% drop in the butterfly population in Europe and a 76% decline in the biomass of flying insects in Germany, with the 29 main groups of insects being: butterflies and moths; beetles; bees, wasps and ants; and flies. With this in mind, scientists from the Biodiversity and Environment Research Centre at University College London evaluated some 750,000 samples, from nearly 20 species, from 6,000 sites around the world.

“Our findings published in Nature reveal that insect declines are greatest in agricultural areas of tropical countries, where the combined effects of climate change and habitat loss are being experienced more profoundly,” the scientists explained in the paper. At the same time, they pointed out that “farmland sites have only half, on average, the number of insects and more than 25% fewer species of insects.” “Farmland in climate-affected areas, where most of the nearby natural habitat has been removed, has lost 63% of its insects, compared to just 7% of farmland where much of the habitat has been preserved.”

It is worth noting that, it is estimated that 87 of the world's main crops depend (totally or partially) on pollinating insects, according to experts. Some of the species of insects that are in danger are: orchid bees in the forests of Brazil (their presence fell by 50%), moths in Costa Rica and bumblebees in Europe and North America.

“Our results show that farmland in these regions has generally lost a large amount of insect biodiversity, relative to areas of primary vegetation. This highlights that climate change can pose a major threat to food security, not only because of the direct impact on crops but also because of the loss of pollinators and other important insects,” the authors wrote in The Conversation. Therefore, they warned that, “farmers are resorting to manual pollination techniques.”

Among the solutions expressed, scientists proposed “reducing the intensity of agriculture by reducing the use of chemicals and a greater diversity of crops. For insects that live in farmland, natural habitat patches act as an alternative source of food, nesting sites and places to shelter from high temperatures. Increasing the amount of natural habitat increases the number of key insects, including pollinators.”

What land should be preserved

Scientists from the University of Georgia created a model that aims to collaborate with developers and public officials to identify which land is most suitable for conservation. It is an algorithm that evaluates a series of factors that, previously, were not taken into account, as explained in the research published in the journal Environmental Management. “Too often, people value land for the buildings it contains. But undeveloped land also has value: in the form of ecosystem services,” explained Puneet Dwivedi, a professor at the Warnell School of Forestry and Natural Resources.

In order to analyze which land to choose, the experts used three factors: water, carbon and habitat. Forests, for example, are highly effective in capturing carbon dioxide. However, assessing how valuable these lands are was not an easy task, even more so when the values of nearby properties are lower than those found in urban centers. “Conservation efforts are almost always on a fixed budget. Our model allows us to find the best plots of land for conservation and maximize the impact over time,” said Dwivedi.

Meanwhile, Fabio Jose Benez-Secanho, a former graduate student at the University of Georgia and project leader, said: “Other models without limit penalties allow the algorithm to select those plots that produce the highest economic values, but were generally scattered throughout the landscape.” “As we added boundary penalties, larger parcels with greater connectivity were selected. Larger protected areas benefit wildlife habitat, biodiversity and other ecological functions. The financial trade-offs of selecting larger plots are relatively low compared to the additional benefits they provide,” concluded the researcher.

KEEP READING: