News coverage of climate change is invariably gloomy and there is often a sense that, even with our best efforts, it may be too late to save the planet. This consensus is based on 9 experts answers from this question: Is it too late to prevent climate change?Is climate change already happening?All experts agreed that climate change is already happening. Dr Michael Wehner, an expert in climatology from Lawrence Berkley National Laboratory in the USA, says “The world is currently at 1.1C above preindustrial temperatures. This is without question. And [IPCC] reports assess the literature finding that our best estimate (a rigorous statistical term) is that human changes to composition of the atmosphere are responsible for ALL of this well observed warming.”Rising temperatures have been carefully documented since the 1850s and the years 2015 to 2021 will be the seven warmest years on record. The impacts of this warming have also been documented – for example sea levels have risen by 4.4mm per year between 2013 and 2021. Some extreme weather events have also been on the rise. Many people are already feeling the impacts of climate change today.

Earth's average surface temperature has warmed ~0.7°C since 1951. This warming is not caused by natural processes like solar radiation or volcanic activity. An increase in greenhouse gases via human activity is highly likely to be the primary driver of recent global warming. This consensus is based on 7 experts answers from this question: Are humans the primary cause of recent global warming?“l’effet de serre”The idea that humans could alter the temperature of our planet is a huge claim and it’s one that dates back to the 19th century. In 1824, French physicist and mathematician Joseph Fourier made an unexpected discovery. The sun gives earth all our warmth (or so Fourier thought). By knowing how much energy the sun emits and the distance to the sun, Fourier calculated what the temperature of earth should be. He calculated the temperature to be a life-stopping -18°C (-64°F). That's odd.The oceans weren’t frozen, life was blooming and the average temperature on earth was a balmy 15°C (59°F). Something was wrong with his assumption. Something must be trapping the heat Fourier thought. He called this trapping of heat l’effet de serre – the greenhouse effect. But it took a while for others to work out what the invisible ingredient could be.

Pharmaceuticals, the chemicals found in medicines and drugs, are widely used across the world and allow us to treat and prevent disease. There is a growing concern that some of these pharmaceuticals are leaching into natural waterways like rivers, streams and lakes. To find out if this poses a problem, we asked 4 experts in toxicology and environmental sciences “Are current pharmaceuticals levels in natural waterways dangerous?”. Here is what we found out. This consensus is based on 4 experts answers from this question: Are current pharmaceuticals levels in natural waterways dangerous?What is the current level of pharmaceuticals in our natural waterways?A USA study found measurable amounts of pharmaceuticals in 80% of the water samples they collected from streams across 30 different states. The issue of drugs in natural waterways is not just in the USA but across the globe. A 2014 review of over 1000 studies found pharmaceuticals residues in 71 countries worldwide.The 2014 review found over 600 different pharmaceutical chemicals in lakes, rivers and ground water globally. These chemicals included antibiotics, painkillers, beta-blockers, contraceptive hormones and antidepressants, amongst others.

Seaspiracy, the Netflix documentary made in March 2021 which exposes the darker side to the fishing industry, has caused much controversy since its release. One of the more dramatic claims made during the film was that, due to fishing, all of the fish in the sea will have disappeared by 2048. To check this fact, we asked 8 experts in fisheries sciences, marine sciences, and ecology ‘Will the oceans be empty of fish by 2048?’, 7 out of 8 answered ‘extremely unlikely’. This consensus is based on 9 experts answers from this question: Will the oceans be empty of fish by 2048?Where did the 2048 prediction come from?Ali Tabrizi, Seaspiracy’s director and narrator, says during the documentary “If current fishing trends continue, we will see virtually empty oceans by the year 2048”. This claim has been echoed across many news articles and blogs since it was made in 2006, but where does it come from?A scientific paper published in Science by Worm and colleagues in 2006 which looked at the decline of marine populations and species. They found that loss of marine biodiversity has important effects on the ecosystem. In one sentence in the concluding paragraph, they also said that the “current trend is of serious concern because it projects the global collapse of all taxa currently fished by the mid-21st century”.

Climate change has been ongoing for some time, but most conversations about the issue focus on the future and what we can do to slow or stop global temperatures rising. Worst case scenarios depict mass migration of people as large areas become uninhabitable, but is anyone feeling the impacts of climate change now? We asked 10 experts in climate change, biometeorology and climatology, ‘Are some people already being impacted by climate change?’, here is what we found. This consensus is based on 12 experts answers from this question: Are some people already being impacted by climate change?What is the evidence that people are being impacted by climate change?All 10 experts responded with ‘Near Certain’ to answer the question ‘Are some people already being impacted by climate change?’. Professor Jennifer Fitchett, an expert in biometeorology from Witwatersrand University in South Africa, says “Many people still think of climate change as a phenomenon that we will only face in the distant future. Perhaps that’s partly because climate change projections about rising temperatures and extreme weather events are tied to future dates: 2030, 2050, or 2100, for instance. But it’s important to realise that we already are experiencing climate change, and have done so for some time now. Over the past century, global temperatures have increased by approximately 1°C. Sea level rise is already starting to affect certain low-lying coastal communities. The world is experiencing more frequent and intense extreme climate events.”Although the impacts of climate change are wide-ranging and occur across the globe, many of them have been carefully recorded and studied. Dr Lisa Schipper, an expert in environmental social science from Oxford University in the UK, says “yes, all over the world. This is best documented in the recent IPCC reports … There are thousands of studies documenting these impacts.”

In order to mitigate the global impacts of climate change, we need to dramatically reduce our carbon emissions, or even better – stop emitting completely. Many countries have recognised the need to switch from fossil fuels to renewable or ‘green’ energy in order to do this. Whilst most of us are in homes that are powered from a mixture of sources from coal to wind, is it feasible that one day everything will be solely from renewable energy sources? We asked 22 experts in renewable energy, engineering and energy systems ‘Is having 100% renewable energy for a country feasible?’ 15 answered likely, here is what we found out. This consensus is based on 22 experts answers from this question: Is having 100% renewable energy for a country feasible?What is renewable energy?Renewable energy is energy that can be quickly replenished. Oil and coal take millions of years to be made, so aren't renewable. Nuclear power uses uranium, also non-renewable. But anything sourced by shorter-term forces in nature like the sun, moon or rain are renewable.Geothermal, solar, hydro, wind, tidal and biomass are all forms of renewable energy as they will not run out in the near future. The capacity for renewable energy is enormous: “The Earth receives 23000 TW of solar energy, while the global energy consumption is 16 TW. Therefore, [100% renewable energy] could be possible even if we capture only 0.07% of the solar energy" says Professor Xiao Yu Wu, an energy expert from MIT.