The United Nations argues that since the 1800s, human activities have been the main driver of climate change, primarily due to the burning of fossil fuels with carbon dioxide as the main greenhouse gases. This is utterly ridiculous. The current concentration of carbon dioxide is about 427 ppm, which means that for every 1,000,000 gas … Read more
Milankovitch cycles are long-term, cyclical changes in Earth’s orbit around the sun and axial tilt that alter the amount of solar energy reaching the planet, influencing long-term climate patterns like ice ages, named after Serbian scientist Milutin Milanković. The three main cycles are: Eccentricity (shape of orbit, ~100,000 yrs), Obliquity/Axial Tilt (angle of tilt, ~41,000 … Read more
A giant cloud of interstellar gas and dust (the solar nebula) collapsed under its own gravity. As it collapsed, it spun faster and flattened into a disk, with most mass concentrating in the center. The central mass became so hot and dense that nuclear fusion of hydrogen began, marking the Sun’s birth as a star. … Read more
The exosphere includes the uppermost region of Earth’s atmosphere as it gradually fades into the vacuum of space. The air in the exosphere is extremely thin – in many ways it is almost the same as the airless void of outer space. The exosphere is directly above the thermosphere; the boundary between these two layers … Read more
The thermosphere is a layer of Earth’s atmosphere that is directly above the mesosphere and below the exosphere. It extends from about 90 km (56 miles) to between 500 and 1,000 km (311 to 621 miles) above Earth’s surface. Temperatures climb sharply in the lower thermosphere (below 200 to 300 km altitude), then level off and … Read more
The mesosphere is a layer of Earth’s atmosphere. The mesosphere is directly above the stratosphere and below the thermosphere. It extends from about 50 to 85 km (31 to 53 miles) above our planet. Temperature decreases with height throughout the mesosphere. The coldest temperatures in Earth’s atmosphere, about -90° C (-130° F), are found near … Read more
Oxygen is primarily made in nature through photosynthesis, a process used by plants, algae, and cyanobacteria. These organisms use sunlight, water, and carbon dioxide to create energy, releasing oxygen as a byproduct. This process has been ongoing since early microorganisms produced oxygen, gradually creating the oxygen-rich atmosphere that exists today. Oxygen is the most abundant … Read more
Oxygen is vital for humans because it enables cells to produce the energy needed to survive and perform all bodily functions. When we breathe in, oxygen enters the bloodstream, travels to the cells, and is used to break down food for energy. The body’s waste product from this process, carbon dioxide, is then carried back … Read more
All life requires nitrogen compounds, e.g., proteins and nucleic acids. Air, which is 79% nitrogen gas (N2), is the major reservoir of nitrogen. But most organisms cannot use nitrogen in this form. Plants must secure their nitrogen in “fixed” form, i.e., incorporated in compounds such as: nitrate ions (NO3−), ammonium ions (NH4+) and urea (NH2)2CO. … Read more
The Hunga Tonga volcano released a relatively small amount of sulfur dioxide for a cooling effect, with estimates ranging from 0.42 million tonnes to 1.5 million tonnes (0.42 to 1.5 Tg) injected into the stratosphere. While this was much less than previous volcanic eruptions like Mount Pinatubo, it still caused a temporary cooling effect primarily … Read more
