Nature-based solutions are essential to combat the adverse effects of climate change

Researchers analyzed strategies for ecosystem conservation and rehabilitation of degraded areas in the second part of the FAPESP 60 Years Lectures.

By Elton Alisson  |  Agência FAPESP – Conservation of ecosystems such as forests, wetlands or areas occupied by natural pasture and restoration of degraded areas are essential to deal concurrently with climate change and biodiversity loss, which are among the main global challenges today.

Implementation of such nature-based solutions is especially important in Brazil, where most of the greenhouse gas emissions that fuel global warming are associated with land use changes, led by deforestation to make way for crops or pasture. Forest fires release the carbon gas stored in plants into the atmosphere, and illegal logging leads to fragmentation and habitat loss, both of which are among the main causes of worldwide species decline.

These points were stressed by researchers who participated in the second part of the FAPESP 60 Years Lectures, entitled “Climate change and biodiversity: scientific advances”, and held on July 21 with Ronaldo Pilli, Vice President of FAPESP, moderating.

“Conservation of intact areas as of now is an option to keep stored carbon where it is. Restoration of degraded areas could be used to sequester carbon from the atmosphere and reconnect natural fragments, potentially benefiting biodiversity,” said Mercedes Bustamante, a professor at the University of Brasília (UnB).

Land use changes account for 24% of emissions globally, she added, but 60% in Brazil. The proportion risen in recent years owing to deforestation, especially in the Amazon.

In 2019, deforestation in Brazil corresponded to the loss of one third of the world’s primary tropical forests. The proportion was 41% in the period 2002-20.

“The loss of primary forest is occurring particularly in indigenous territories, which have always had very little deforestation. On the contrary, forests have long been protected there,” Bustamante said.

Although deforestation is happening on a larger scale in the Amazon, the phenomenon is not confined to that biome. In 2020, the Cerrado (Brazilian savanna) lost an area four times the size of metropolitan São Paulo. Deforestation has also increased in the Atlantic Rainforest.

“These land use changes in Brazil are a two-way street. Conversion of native vegetation into cropland, associated with the rising frequency of forest burnings, has a direct impact on greenhouse gas emissions and will also hurt the agricultural sector, which will suffer most from climate change and the effects of alterations in temperatures and rainfall,” Bustamante said.

Impact on agriculture

These trends also featured in the presentation by Paulo Artaxo, a professor at the University of São Paulo’s Physics Institute (IF-USP) and a member of the steering committee for the FAPESP Research Program on Global Climate Change (RPGCC). Artaxo outlined the findings of a study by researchers at Brazil’s National Space Research Institute (INPE) predicting that temperatures in the Central region, a major agribusiness hub, will rise 4 °C-5.5 °C between 2071 and 2099.

According to a 2019 study by scientists in the Agricultural Informatics Unit of the Brazilian Agricultural Research Corporation (EMBRAPA), Artaxo continued, large swathes of Brazil are fast becoming drier. The Northeast was once the only drought-ridden region, but lack of rainfall now also afflicts Goiás and Mato Grosso, both major producers of soybeans and beef cattle.

“The economy based solely on meat and soybeans, for example, may not be competitive in ten years’ time or even by the end of this decade,” Artaxo said.

Global evidence of climate change is extensive and includes the rising frequency of extreme weather events such as the recent floods in Belgium and Germany, heatwaves in the US and Canada, water shortages in Brazil, and warming of the oceans and atmosphere.

Carbon emissions, he explained are rapidly raising the levels of gases that control the planet’s climate. Carbon dioxide (CO₂) levels are up 66% since 1750, methane 259%, and nitrous oxide (N₂O) 120%. The composition of the atmosphere has changed as a result. Earth’s average temperature has risen 1.2 °C.

“That may not sound like a very big temperature rise, but it’s very significant for the basic functioning of an ecosystem, and has contributed to the increase in the frequency of extreme weather events,” Artaxo said.

The average temperature on land has risen 1.7 °C, in fact: the oceans absorb huge amounts of heat and warm up less quickly than land masses. “We’ve already exceeded the upper limit for a safe temperature rise on land, which is 1.5 °C according to the IPCC [Intergovernmental Panel on Climate Change],” Artaxo added.

In the Northeast of Brazil, for example, the temperature has risen 2.2 °C-2.5 °C in the last 110 years. In the Arctic, it has risen more than 3 °C.

“This very significant temperature rise affects the functioning of ecosystems, biodiversity and human health, and has enormous socio-economic impacts,” Artaxo stressed.

Impacts on biodiversity

Climate change may become the main driver of global biodiversity loss from 2050 on, according to Carlos Joly, a professor at the State University of Campinas’s Biology Institute (IB-UNICAMP) and a member of the steering committee for the FAPESP Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable Use (BIOTA-FAPESP).

“A huge number of factors have exerted enormous pressure and led to the disappearance of a great many species of invertebrates. These factors range from global warming and changes in rainfall distribution to excessive use of fertilizer and the introduction of exotic species, among others,” Joly said.

Some endangered species of invertebrates, such as bees, are extremely important to the pollination of key crops grown in Brazil and elsewhere, he added.

The pace of species loss suggests the world runs a serious risk of seeing a sixth mass extinction in the decades ahead. “The biodiversity crisis is reaching a very dangerous limit,” Joly said.

While the ongoing public health crisis caused by the COVID-19 pandemic will be sorted out in the next two years thanks to vaccination, and the climate emergency could wane in 100-150 years as greenhouse gas emissions steadily fall, the global loss of biodiversity may be irreversible, Artaxo warned. “We won’t recover the species that are going extinct now. Extinction rates must be reversed before too much damage is done to ecosystem services [provided by nature, such as clean water],” he stressed.

FAPESP’s activities and funding for research on biodiversity and climate change have been fundamental to advance these agendas on a global scale, according to the participants in the event.

“Different countries and supranational entities, as well as responsible corporations and political parties, are increasingly investing in an agenda that prioritizes these two topics,” said Marco Antonio Zago, President of FAPESP.

“In Brazil, FAPESP, the ABC [Brazilian Academy of Sciences], the SBPC [Brazilian Society for the Advancement of Science], the ACIESP [the São Paulo State Academy of Sciences] and our universities have led a movement to foster the development of knowledge based on research regarding biodiversity and global climate change,” Zago said.

The event was recorded and can be watched in full at: https://www.youtube.com/watch?v=PEP56Gnk3YU.