Your Dog’s Carbon “Paw Print”

The U.S. is the world’s second largest emitter of greenhouse gases, but Trump, for the second time, has pulled the country out of the Paris Climate Agreement that addresses global warming. At the UN last week, a day before China made its pledge, Trump praised the benefits of fossil fuels and called climate change “the greatest con job ever perpetrated on the world.” Climate activist and author Bill McKibben wrote that Trump’s remarks at the UN were stupid, and that 2025 will be noted by historians as the passing of technological, economic, and political leadership from the U.S. to China in the span of just eight months. 

In reaction to China’s announcement, the chief climate officer of the European Union, Wopke Hoekstra, was quick to criticize China’s intention, saying that it was disappointing given the country’s immense greenhouse gas footprint and such a low goal would make it challenging to meet the world’s climate goals. Europe Commission President Ursula von der Leyen said that the EU would set a target of cutting up to 72 percent of emissions, but that had not yet been agreed upon.

Lula Da Silva, president of Brazil, and UN Secretary-General António Guterres, convened a Climate Summit of about 100 nations as part of last week’s General Assembly, where they committed to finalize their climate targets ahead of the COP30 meeting in Brazil in about six weeks.

Despite the retreat of the U.S., global investment in renewable technology grew in the first six months of this year by about ten percent more than the same period in 2024, according to the research group Zero Carbon Analytics.

The Planetary Boundaries Science Lab at the Potsdam Institute for Climate Impact Research revealed that last year, ocean acidification had breached a boundary for the first time. The increasing acidity of the ocean is caused by the absorption of excess CO2 from the atmosphere, which they said was driven mainly by burning fossil fuels made worse by deforestation. 

Acidification makes it harder for organisms like oysters and corals to build their shells or skeletons, disrupting marine ecosystems and potentially affecting food security and coastal protection. Corals, both in cold water and in the tropics are at risk, as are Arctic environments. 

Currently, the institute says there are only two planetary boundaries that are within safe limits—air pollutants and the ozone layer in the stratosphere—successes they attribute to international action on aerosol emissions, although parts of the world, such as South and East Asia, and parts of Africa and Latin America, are still experiencing dangerous particulate pollution.

The other boundaries that have been breached are climate shifts in temperature and weather patterns, changes in land systems like deforestation, freshwater use, biosphere functioning and resilience, biogeochemical flows such as water or nitrogen cycles, and novel entities like chemicals and microplastics.

A new study from Penn State found that heat waves are happening in rivers too, and they’re accelerating faster than and lasting nearly twice as long as the heat waves in the air. It’s a surprising finding, given that many rivers are fed by snowmelt and underground streams, but the team found that periods of abnormally high temperatures in rivers are becoming more common, more intense, and longer-lasting than they were 40 years ago. Lead author Li Li (李黎) wrote in The Conversation that the increased heat puts stress on aquatic ecosystems and can also raise the cost of treating drinking water. 

The team collected river data at nearly 1,500 sites in the contiguous United States between 1980 and 2022. They found that temperatures rose above 59 °F (15 °C)—a threshold that can stress many species—at 82 percent of study areas for an average of 11.6 days per year. The places where the waters warmed the fastest were in the Northeast, the Rocky Mountains, and Appalachia.

The authors say climate change is driving river heat waves, as rising air temperatures affect water conditions. Changing precipitation patterns with global warming are shrinking winter snowpacks, leaving less meltwater to support river health. Low, slow-moving water warms more easily and holds less oxygen, creating dangerous conditions for aquatic life and increasing the chances of large-scale die-offs. The study adds that human activities, such as dams and agriculture, play a secondary role in shaping how and where rivers are most vulnerable to these impacts.

The study was published in the journal Proceedings of the National Academy of Sciences (PNAS).

The University of Nottingham has, and they’ve released a new study published in the journal Frontiers in Nutrition - Nutrition and Sustainable Diets, saying that plant-based foods, rather than red-meat options, are best not only for man's best friend but also for the Earth.

The researchers looked at 31 different types of dry dog foods sold in the UK, from ones based in poultry, lamb, and beef to others that were vegan and vegetarian. They found that plant-based diets for pets had the lowest impact across several measures, including greenhouse gas emissions, the polluting effects of their production on soil and water, freshwater withdrawal, and the land needed to produce the foods.

For example, they say that over nine years of its adult life, if a 20 kg Labrador Retriever, currently the most popular dog in the United Kingdom, were fed a beef-based diet, it would require 57 football fields worth of land to grow its food. A dog fed a plant-based diet would require 1.4 fields.

Also, the plant-based foods were not inferior. A study the team published earlier this month in PLOS One found vegan dog food provided similar nutrition to meat-based fare in terms of its protein content and individual amino acids, fatty acids, major and trace elements, vitamin D, and all B-vitamins. Notably, deficiencies in plant-based diets mirrored those commonly seen in plant-based human diets, such as iodine and B vitamins.