A variety of factors influence Earth’s climate, such as land, atmosphere, and ice, but not all aspects need to be perfectly modeled to produce useful forecasts of global temperature in climate models. State-of-the-art climate models have successfully forecasted global average surface temperatures over the past few decades.
Global surface temperatures are increasing consistent with the long-term trend projected by climate models, which are useful tools for understanding the consequences of continued greenhouse gas emissions.
What Happer says is like saying, “Sun cannot cause skin cancer. The sun is natural, it’s something plant love, they grow better with more sunshine!”
The link between global warming and atmospheric CO2 levels is well-established; in fact, increases in CO2 have warmed the planet multiple times over the last million or so years. Science shows unambiguously that current climate change is caused by human-emitted greenhouse gases. Based on this knowledge, scientists are confident that any grand solar minimum will not result in a cooling trend, as changes in total solar irradiance are not projected to be enough to offset human-caused warming.
Climate scientists use models to simulate Earth’s climate system and project the rate of global warming caused by human activities. State-of-the-art climate models have successfully forecasted global average surface temperatures over the past few decades.
“This video is misleading in so many ways it’s hard to know where to begin. For a start there’s a repeated assertion that climate “alarmists” won’t enter debate on climate change, but there are many examples of renowned climate scientists such as Gavin Schmidt, Michael Mann and David Karoly entering into debates with climate change denialists. Many scientists have found such debates to be unhelpful as they give the false impression of balance despite there being broad consensus among climate scientists…”
Atmospheric CO2 levels have increased by 47% since 1850, due to agricultural development, the burning of fossil fuels, and other human activities. Since 1950, approximately 100% of the global warming trend is attributed to increased CO2 emissions. Although CO2 has increased plant growth in some regions of the world, it can also negatively impact natural ecosystems and human societies.
CO2 can increase plant growth but its effects, which decrease with higher concentrations, are limited by the availability of other plant nutrients, such as nitrogen and phosphorus. CO2 emissions can negatively impact natural ecosystems through global warming—e.g. by increasing evaporation and drying up soils in some regions or increasing heavy precipitation in others.
“This article is a mixture of misdirection, misleading claims, and outright falsehoods. The author attempts to paint a picture of current climate change as simply a continuation of natural changes that have occurred in the past. But this neglects the clear evidence that climate change over the last two centuries has been shown to be largely man-made, that it is much more rapid that anything we have seen in the last two thousand years if not longer, and that it is occurring in the context of a globe with more than 7 billion human inhabitants.”
Climate scientists use models to simulate and study different aspects of Earth’s climate system, and to project the rate of global warming caused by human activities. These models do, in fact, simulate the rate of global warming well, and models run in the past accurately projected the rate of warming we are currently experiencing—that includes model projections from 1988.
