Joint insolation and ice sheet/CO₂ forcing on northern China precipitation during Pliocene warmth

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.

Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...

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...

The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...

Paleozoic Plate TectonicsThe Paleozoic Era lasted from about 541 to 252 million years ago. During this time, Earth's surface changed dramatically. The movement of tectonic plates, large pieces of Earth's crust, caused continents to shift, oceans to open and close, and mountains to rise. These slow but powerful movements shaped the land and affected life. By the end of the Paleozoic, most of Earth's land had joined into one supercontinent, Pangaea.Science and Engineering Practice (SEP):...

Cenozoic Plate TectonicsThe Earth's surface is always changing. The Cenozoic Era, which began about 66 million years ago and continues today, has been a time of major changes in Earth's land and oceans. Large pieces of Earth's crust, called tectonic plates, have moved to form mountains, shifting continents and opening new ocean basins. These movements have shaped the world as we know it.During the Cenozoic, the continents moved into their current positions. Mountain ranges like the Himalayas...