200ppm

200ppm refers to a concentration of 200 parts per million. This unit of measurement is commonly used to express the relative amounts of a substance within a larger mixture. The "parts per million" system indicates that for every one million units of the total mixture, there are 200 units of the specific substance.

In environmental science, 200ppm is a notable figure when discussing atmospheric carbon dioxide (CO2) levels. Historically, pre-industrial atmospheric CO2 concentrations were around 280ppm. The increase in CO2 levels, which has surpassed 400ppm in recent times, is a significant factor in discussions surrounding climate change and global warming. The milestone of 200ppm represents a point of reference in understanding the trajectory of these atmospheric changes over geological and human timescales.

Beyond atmospheric gases, 200ppm can be applied in various other contexts. For instance, it might describe the concentration of a trace element in a solution, a pollutant in water, or a specific additive in a manufactured product. The significance of 200ppm in any given scenario is entirely dependent on the substance being measured and the medium it is present in. Its interpretation requires knowledge of the specific application and the properties of the measured component.