Increased mercury pollution revealed by tree rings from the China's Tianshan Mountains

Tree Rings, Ice Cores, and VarvesScientists use natural records such as tree rings, ice cores, and varves to study past climate conditions. These records reveal temperature, precipitation, and atmospheric composition over thousands of years.Tree Rings – Trees grow new rings each year. The thickness of each ring reflects climate conditions like droughts or wet seasons.Ice Cores – Ice sheets trap air bubbles. Scientists analyze these layers to learn about past temperatures and greenhouse gas...

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.

Health Hazards of Air PollutionAir pollution doesn’t just harm the environment; it can also profoundly affect human health. Breathing polluted air can cause problems like asthma, allergies, lung diseases, and even heart conditions. Tiny particles, harmful gases like carbon monoxide, sulfur dioxide, nitrogen oxides, or chemicals from vehicles and factories can enter our lungs and bloodstream. Both outdoor and indoor air pollution can impact people, especially children, the elderly, and those...

There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...

Outdoor Air PollutionAir pollution happens when harmful gases, dust, smoke, or chemicals enter our air. These pollutants can come from cars, factories, wildfires, or everyday activities like aerosol sprays. There are two types of pollution: indoor and outdoor air pollution. Outdoor air pollution, in particular, includes emissions released into the open air, where they mix with the atmosphere and can travel great distances. Polluted air can cause health problems for people, harm animals, damage...

Indoor Air PollutionWhen we think of air pollution, we often imagine smoggy skies or factory smoke, but indoor air pollution can be just as harmful. Air pollutants like dust, mold, chemicals from cleaning products, smoke, and gases like carbon monoxide can build up inside homes, schools, and buildings. Poor ventilation can make the problem worse, leading to health issues like allergies, asthma, or headaches. Learning about indoor air pollution helps us understand where these pollutants come...