Glaciers are melting, sea levels are rising, forests are being decimated, extreme weather is accelerating and wildlife is scrambling to keep pace with unprecedented rates of extinction reported. It has become clear that humans have caused most of the past century’s warming by releasing heat-trapping gases as we power our modern lives. Called greenhouse gases, their levels are higher now than at any time in the last 800,000 years.

While many people think of global warming and climate change as synonyms, scientists use “climate change” when describing the complex shifts now affecting our planet’s weather and climate systems—in part because some areas actually get cooler in the short termGlobal warming” refers to the rise in global temperatures due mainly to the increasing concentrations of greenhouse gases in the atmosphere.

= The most basic and urgent information


Q: What is the difference between climate and weather?

A: “Weather is what’s happening in the atmosphere, on any given day, in a specific place. Local or regional weather forecasts include temperature, humidity, winds, cloudiness, and prospects for storms or other changes over the next few days. Climate is the average of these weather ingredients over many years. For example, it might be raining in Riverside today, but we have a dry, hot climate because on average, it only rains a few days of the year. Weather can day to day but climate changes slowly, over decades or centuries.” More at UC Riverside

Q: What is the difference between climate change and global warming?

A: Global warming is a driving force behind climate change. It refers to the overall warming of the planet over a long period of time and is driven by excessive greenhouse gas emissions. Climate change both encompasses global warming and refers to its effects. Warmer temperatures have affected our climate in numerous ways, changing weather patterns and consequently changing other natural elements on Earth, such as oceans, forests, biodiversity, etc. More at NASA.


Q: What causes global warming?

A: Global warming occurs when carbon dioxide (CO2) and other air pollutants and greenhouse gases collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth’s surface. 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. More at NRDC

Q: Are humans the major cause of global warming?

A: Scientists have devised different methods to answer this question. Meteorologists and oceanographers compare the climate patterns they observe with patterns developed using sophisticated models of Earth’s atmosphere and ocean. By matching the observed and modeled patterns, scientists can positively identify the “human fingerprints” associated with the changes, and they can also attribute the proportion of those changes to human activities. More at Union of Concerned Scientists

Q: Could the sun be responsible?

A: According to the United Nations’ Intergovernmental Panel on Climate Change (IPCC), the current scientific consensus is that long and short-term variations in solar activity play only a very small role in Earth’s climate. Warming from increased levels of human-produced greenhouse gases is actually many times stronger than any effects due to recent variations in solar activity. More at NASA

Q: Hasn’t the earth warmed before?

A: In the past, it changed naturally over thousands of years. Both the speed and the cause are different now. The warming of the earth is now taking place in decades because of increasing amounts of greenhouse gases in the atmosphere, blanketing the earth. A clear, simple video from NOAA here

Q: Why does it matter that the world is warming?

A: Because the consequences are so dire: The earth will experience accelerated heat waves, precipitation, sea level rise, food shortages, and. economic impacts. It will face fresh water availability, impacts on biodiversity and ecosystems, the destruction of forests, the death of sea life and the destruction of coral reefs. More at NASA


Q: Where does our energy come from?

A: In 2019, the United States got 80% of its total energy from oil, coal, and natural gas, all of which are fossil fuels. Approximately 11.4% came from renewables (principally biomass, hydropower, wind, geothermal, and solar). Nuclear, a clean but not renewable source of energy provided another 8.4%. We depend on those fuels to heat our homes, run our vehicles, power our industry and manufacturing, and provide us with electricity. More at EIA.

Q: Do greenhouse gases come from fossil fuels?

A: The largest source of greenhouse gas emissions from human activities in the United States is from burning fossil fuels for electricity, heat, and transportation. … Approximately 63 percent of our electricity comes from burning fossil fuels, mostly coal and natural gas. More at the EPA.

Q: What are the 4 main greenhouse gases and why does CO2 get most of the attention?

A: Carbon dioxide (CO2) is the primary greenhouse gas, responsible for about 75% of emissions and lingering in the atmosphere for thousands of years; Methane (CH4), the main component of natural gas, it only stays in the atmosphere about 12 years but is 84 times as potent as CO2), responsible for about 16% of emissions; Nitrous Oxide (N2O), responsible for about 6% of emissions but 264 times more powerful than CO2 over 20 years. Agriculture is the primary source. Finally, the industrial gases, responsible for 2% have a heat trapping potential thousands of times greater than CO2 and stay in the atmosphere for hundreds to thousands of years. More at National Geographic

Q: What are the effects of greenhouse gases?

A: Greenhouse gases have far-ranging environmental and health effects. They cause climate change by trapping heat, and they also contribute to respiratory disease from smog and air pollution. Extreme weather, food supply disruptions, and increased wildfires are other effects of climate change caused by greenhouse gases. The typical weather patterns we’ve grown to expect will change; some species will disappear; others will migrate or grow. More at National Geographic

Q: What is the greenhouse effect?

A: It is the natural process that warms the Earth’s surface. The process is called the greenhouse effect because the exchange of incoming and outgoing radiation that warms the planet works in a similar way to a greenhouse. The Earth and the Sun work in a similar fashion. The sun shines through the Earth’s atmosphere and the earth’s surface warms up. Some of the Sun’s energy is reflected directly back to space, the rest is absorbed by land, ocean, and the atmosphere. The greenhouse gases in the atmosphere trap heat radiating from Earth toward space. More at the Climate Reality Project


Q: Is it too late to prevent climate change?

A: We can’t stop climate change — because it’s already here, and it’s already too late to reverse many of its catastrophic effects. What’s true is that things are on track to get much worse over the course of this century, and that if we’re going to stop those things from happening, society is going to have to start hitting some important deadlines fast. More at Live Science