Australia’s frog species, already threatened by habitat destruction and disease, are being put under extra pressure by shifting rainfall and rising temperatures from climate change. Some of Australia’s leading frog experts are worried that serious impacts could be unfolding out of sight, with one saying climate change could push certain species to extinction before they are documented by science. Many of Australia’s frogs are found nowhere else in the world, but the continent is also at the coalface of climate impacts with extreme heat, droughts and rising temperatures. Frogs are known to be at a high risk from climate change because they are ectotherms, animals with a body temperature regulated by their environment. Global populations of frogs and other amphibians have already been devastated by chytrid fungus, a disease that broke out in the 1980s and 90s. Now climate change could wreak havoc too. Prof Michael Mahoney, of the University of Newcastle, has spent … [Read more...] about Climate change puts additional pressure on vulnerable frogs
When global warming become climate change
Economics and climate change are both complex subjects that contain significant areas of uncertainty – especially when it comes to making long-term predictions. Inevitably, therefore, it's impossible to accurately predict with any certainty the long-term economic costs of avoiding or coping with the impacts of climate change. Part of the complexity stems from the number of factors involved. For example, the cost of reducing future emissions will depend on the prevailing prices of fossil fuels and alternative forms of energy – which in turn will depend on factors as diverse as depletion of energy reserves, economic growth, demographics, government incentives, cost of metals and technological progress. Similarly, the cost of dealing with rising temperatures will depend – among many other things – on the sensitivity of the climate to greenhouse gases, the location and severity of regional climate impacts, and the mechanisms of climate feedback loops. Even if there … [Read more...] about What is the economic cost of climate change?
So far, global warming has been limited to a rise of around 0.75C since the end of the 19th century. This sounds like a small change, but the scientific evidence suggests it is already leading to a range of impacts around the world. As we'll explore in future questions, these impacts includes changes to sea level, rainfall patterns, ecosystems and some kinds of extreme weather. It's worth noting that the temperature rise observed to date isn't spread evenly around the planet. As can be seen clearly in maps of temperature change (such as those created by Nasa), the increase has been particularly steep in the Arctic, where the climate system is more sensitive to warming than most of the rest of the world, partly due to feedback loops in the local climate that amplify the warming. More importantly, however, is that the temperature rise observed so far is not the chief cause of concern. More worrying is the significantly larger temperature rise (and associated changes in rainfall, … [Read more...] about Climate change: Does a small temperature rise actually matter?
CO2e, or carbon dioxide equivalent, is a standard unit for measuring carbon footprints. The idea is to express the impact of each different greenhouse gas in terms of the amount of CO2 that would create the same amount of warming. That way, a carbon footprint consisting of lots of different greenhouse gases can be expressed as a single number. For example, in 2009, the UK released 474 million tonnes of CO2. But if you include its emissions of methane, nitrous oxide and F-gases, the country's total emissions work out at 566 million tonnes of CO2e. In other words, those extra gases added the equivalent of 92 million extra tonnes of CO2. Standard ratios are used to convert the various gases into equivalent amounts of CO2. These ratios are based on the so-called global warming potential (GWP) of each gas, which describes its total warming impact relative to CO2 over a set period – usually a hundred years. Over this time frame, according to the standard data, methane scores 25 … [Read more...] about What are CO2e and global warming potential (GWP)?
Exxon Mobil Corp on Tuesday scored a win in a closely-watched case after a judge ruled that the company did not hide the true cost of climate change regulation from investors. Justice Barry Ostrager in Manhattan Supreme Court ruled that New York Attorney General Letitia James failed to produce any evidence that investors were misled. The case, filed in October 2018, was the first of several climate change lawsuits against major oil companies to go to trial. 'Nothing in this opinion is intended to absolve Exxon Mobil from responsibility for contributing to climate change through the emission of greenhouse gases,' he added. 'But Exxon Mobil is in the business of producing energy, and this is a securities fraud case, not a climate change case.' Exxon Mobil Corp. hailed the ruling in a trial that it said stemmed from a 'baseless investigation.' Exxon Mobil Corp on Tuesday scored a win in a closely-watched case after a judge ruled that the company did not hide the true cost of … [Read more...] about Exxon wins first climate change lawsuit against a major oil company as judge rules they did not mislead investors