Popular insecticides harm birds in the United States

Nature Sustainability

The increased use of neonicotinoid pesticides in the continental United States may have impacted bird populations and reduced bird diversity, according to a paper published this week in Nature Sustainability. 

Overall tree swallow populations declined by 49% between 1966 and 2014, according 

to the North American Breeding Bird Survey. A PinP photo.

Bird biodiversity is declining at a marked rate. Bird populations in the United States have decreased by 29% since 1970, which has been attributed to various factors including the increased use of pesticides in agricultural production. Nicotine-based pesticides — known as neonicotinoids — have been used increasingly in the United States over recent decades.  Previous research has shown that neonicotinoids are potentially toxic to birds and other non-target species. However, the impact of these pesticides on bird diversity in the United States is unclear. 

Madhu Khanna and colleagues studied the effects of neonicotinoids on birds in the United States from 2008–2014. They analysed data from the North American Breeding Bird Survey to identify county-level changes for four different bird species groups — grassland birds, non-grassland birds, insectivorous birds and non-insectivorous birds — and combined this with county-level data on pesticide use. 

The authors found that an increase of 100 kg in neonicotinoid usage per county, a 12% increase on average, contributes to a 2.2% decline in populations of grassland birds and 1.6% in insectivorous birds.  By comparison, the use of 100 kg of non-neonicotinoid pesticides was associated with a 0.05% decrease in grassland birds and a 0.03% decline in non-grassland birds, insectivorous birds and non-insectivorous birds. Since impacts accumulate, the authors also estimate that, for example, 100 kg neonicotinoid use per county in 2008 reduced cumulative grassland-bird populations by 9.7% by 2014. These findings suggest that neonicotinoid use has a relatively large effect on population declines of important birds and that these impacts grow over time. The authors also found that the adverse impacts on bird populations were concentrated in the Midwest, Southern California and Northern Great Plains.

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New Studies Show Farm Chemicals Are Affecting More Than Bees. Bird Populations are Declining, Too. Is modern agriculture's hold on nature becoming a death grip?

Agrochemicals speed the spread of deadly parasites

CLIMATE&CAPITALISM

The schistosoma parasite worm. Image credit -
David Williams, Illinois State University.

Even low concentrations of pesticides can increase transmission and weaken efforts to control the second most common parasitic disease. Details here.

Global death rate from rising temperatures projected to surpass the current death rate of all infectious diseases combined

The Climate Impact Lab

A PinP photo.

This summer, the world is experiencing record hot temperatures: A weather station in Death Valley, California, clocked one of the hottest temperatures ever observed on Earth. Simultaneously, the coronavirus pandemic’s devastating mortality impact and economic fallout are demanding society prioritize public health like never before. Details here.

Theoretical physicists say 90% chance of societal collapse within several decades

Vice

This photo shows a logging train on the CP Rail mainline in British Columbia, Canada. It depicts man's assault on Earth's forests as it was happening one hundred years ago, in 1920. Photo credit - UBC Library Digitization Centre.

Deforestation and rampant resource use is likely to trigger the 'irreversible collapse' of human civilization unless we rapidly change course. Details here.

The second-largest ice sheet in the Arctic - Canada's Milne sheet, has collapsed.

This animation shows the sheet rapidly receding, losing almost half its mass.

https://twitter.com/ECCC_CIS/status/1290740808170307584?s=20

The Canadian Ice Service.

‘Negligible’ long-term impacts on climate from COVID-19 restrictions

Nature Climate Change

Empty streets during the Covid shutdown in Zaragoza City, Spain, Mar. 2020.
A Wikimedia photo.

The decline in greenhouse-gas emissions and air pollutants, as a result of policies to prevent the spread of COVID-19, will have a negligible impact on long-term warming and may lead to cooling of just 0.005–0.01 °C by 2030, suggests a paper in Nature Climate Change. However, the findings also suggest that if a ‘green recovery’ is pursued, warming could possibly be kept within the 1.5 °C limit above pre-industrial levels by 2050.

The enforcement of policies to limit the spread of COVID-19 has had a significant impact on travel and work. This lack of mobility has led to substantial declines in greenhouse-gas emissions and air pollutants. Previous research has examined the immediate impacts of COVID-19 policies on emissions; however, the long-term impacts of these policies are not well understood.

Piers Forster and colleagues analysed mobility data from 123 countries to estimate emission changes due to the COVID-19 restrictions from February to June 2020. Their analysis suggests that the reductions in emissions are likely to have peaked in April 2020. The authors suggest that nitrogen oxides (NOx) declined by 30% in April, which contributed to short-term cooling. However, this was offset by a 20% decline in sulfur dioxide (SO2), which weakened the aerosol cooling affect and contributed to short-term warming. They use these estimates to project future changes and compare them to a baseline scenario of current national policies. They found that these short-term effects end by 2025, leaving a longer term slight cooling of 0.01 °C from reduced atmospheric concentrations of carbon dioxide compared to concentrations under baseline policies.

To assess the longer-term impacts, the authors modelled four recovery scenarios, including a fossil fuel-based recovery and green stimulus packages. They suggest that the different scenarios have a minimal impact on the 2020–2030 climate response, but that differences emerge after 2030. They find that the two-year ‘blip pathway’, where the economic recovery maintains current investment levels, and a recovery with fossil fuel stimulus are likely to result in warming of over 1.5 °C [NOT: 2 °C] by 2050. Conversely, choosing a strong green recovery that includes low-carbon energy supply as well as energy efficiency and does not support bailouts for fossil firms could limit warming by 0.3 °C and keep warming within 1.5 °C above pre-industrial levels.

The authors highlight that economic recovery choices will affect the warming trajectory by the mid-century and argue that a green recovery is important for ensuring the goals of the Paris Agreement are met.

Climate change: Frequency of extreme droughts across Europe predicted to rise

Nature Research

Photo "drought" by bartoszjanusz is licensed under CC0 1.0

The frequency of record-breaking two-year droughts, such as the 2018–2019 Central European drought, is expected to rise by the end of the century if projected greenhouse gas emissions aren't reduced, according to a study published in Scientific Reports.