Recently the term “climate anxiety” has been used to better describe our growing concerns about climate change. While there is evidence that climate anxiety can be identified and reliably measured, what’s less clear is how it relates to mental illness. Mental health providers across the world are noting the presence of climate anxiety in their patients; however, the degree to which it is influencing mental illness is not yet clear, though evidence addressing this question is slowly growing.

For years now, mental health clinicians have seen climate anxiety influencing presentations of mental illness in a variety of ways, some extreme. Recent studies are starting to look at links between climate anxiety and mental illness in larger samples to help better understand the directionality of their relationship. In a U.S. survey of more than 340 people published in 2018, climate concerns were associated with depressive symptoms (症状). Ecological coping, which includes pro-environmental behaviors such as reducing energy consumption, appeared to be protective against depression, indicating that climate concerns and the poor coping skills used to address them could be causing depressive symptoms.

So who might be more at risk of mental illness secondary to the uncertainties around climate change? Unsurprisingly, climate anxiety appears higher in individuals with more concern about environmental issues at baseline and those already experiencing direct effects of climate change. Climatologists also face increased risk given their in-depth knowledge on the issue coupled with the upsetting task of trying to convey it to individuals and governments that often deny or downplay it. People with high levels of neuroticism, a personality trait that increases susceptibility to mental illness, are also likely to be at high risk.

Some individuals report adaptive responses to climate anxiety like adopting pro-environmental behaviors and participating in collective action, while others are unable to respond behaviorally at all. It’s not yet clear how these varying reactions manifest (呈现) on a population level and how they’re influencing humanity’s response to climate change. However, a recent survey of nearly 200 people found that, while climate anxiety was associated with an emotional response to climate change, it was not correlated with a behavioral response.

If this is true for humanity as a whole, we must urgently help motivate the anxious among us. Doing so successfully will require many approaches, such as delivering cognitive-behavioral therapy (认知行为疗法) to the most severely affected and demonstrating to entire populations that change is possible by better publicizing productive efforts by organizations to reduce their carbon footprints. We can’t let climate anxiety stop us from responding to climate change, because now, more than ever, we need action, not inaction.

Atmospheric (大气层的) rivers are long and narrow bands of water vapor (水蒸气) in Earth’s atmosphere, which are called “large rivers in the sky”. These rivers form over warm ocean waters. They are huge. They can be 930 miles long and one-third that wide.

Like real rivers, they carry huge amounts of water. These large streams of small water drops are blown by wind over land. When that happens, the water vapor cools down and condenses (凝结). Atmospheric rivers can be good. They bring water to dry areas. However, they can cause huge, fast-moving storms. Some cause snowfalls that bury towns. They are also the main cause of floods on the U.S. West Coast.

Atmospheric rivers are hard to predict. But scientists are working to change that. Marty Ralph, a scientist who works at the University of California, directs the Center for Western Weather and Water Extremes (CW3E). They created the first computer model to predict atmospheric rivers on the U.S. West Coast. This model uses a program that runs on a computer to create a model of a real-world event. CW3E also studies atmospheric rivers using planes. Pilots drop instruments into atmospheric rivers to collect information like temperature and wind speed, which helps with forecasting.

Will climate change affect atmospheric rivers? Climate change happens naturally over a long period of time. But today, it is largely caused by human activities and is causing the Earth to warm, which affects atmospheric rivers.

Atmospheric rivers are pushed by the wind. Those winds are driven by the temperature differences between the poles and the equator (赤道). But the poles are also warming faster than areas near the equator. That makes the temperature difference between the areas smaller. This can make winds weaker.

Climate change might not cause more atmospheric rivers. But there may be very, very wet seasons and very, very dry seasons. Such a seesaw in rainfall could make it harder to manage what water there is.

A new study suggests climate conditions in the Sahara Desert, one of hottest, driest and most deserted areas in the world, have changed from wet to dry a about every 20,000 years.

But previous evidence has suggested the Sahara did not always experience such extreme heat and dry conditions. At times, the Sahara Ranged to a very wet climate. This permitted plants and animals to develop and grow and led to the creation of human settlements. Now, they have discovered more evidence, which, the lead researcher David Mc Gee says, supports the idea that the Sahara's climate kept changing between wet and dry about every 20,000,years.

McGee reported these climate changes were mainly driven by changes in the Earth's(地轴)as the planet travels round the sun .This process affects the amount of sunlight between seasons. Every 20,000 years the Earth receives more strong summer sunlight. When the Earth's axis changes again, the amount of sunlight is reduced. This season change happened continuously every 20,000 years. The other part of the season produced rainy conditions, resulting in a wetter, greener, plant-rich environment. When the rainy activity weakens, the climate becomes hot and dry, like the Sahara remains today.

The scientists based their research on dust collected from ocean sediment(沉积物)in the Atlantic Ocean bottom off the coast of West Africa. The dust contained layers (层)of ancient sediment built up over millions of years. Each layer could contain traces of Saharan dust as well as the remains of life forms. This information was used to assess over what time period the dust had built up. This led to the overall finding that the Saharan changes from wet to dry climates happened every 20,000 years.

David McGee said that today we only see the Sahara Desert as an extremely deserted and “inhospitable” place. The new study suggests that the area's climate has changes between grasslands and a much wetter environment, and back to dry climates, even over the last quarter million years. McGee says he thinks the latest research can be valuable in studying the Sahara's history as it relates to human settlement.