Scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect” warming those results when the atmosphere traps heat radiating from Earth toward space. Normally, this radiation would escape into space—but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. That's what's known as the greenhouse effect.  Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as "forcing" climate change. Gases, such as water vapor, which respond physically or chemically to changes in temperature, are seen as "feedbacks." Citations are important for a journal to get impact factor. Impact factor is a measure reflecting the average number of citations to recent articles published in the journal. The impact of the journal is influenced by impact factor, the journals with high impact factor are considered more important than those with lower ones. To increase the visibility and ease of use of open access scientific and scholarly journals PrimeOA Publications top online publishing journals are indexed in different indexing and archiving services.