Study shows 'worst' climate projections 'no longer plausible'

Study shows ‘worst’ climate projections ‘no longer plausible’

According to a new study that shows that efforts to reduce emissions help keep warnings under control, the world is unlikely to reach the “worst-case scenario” of climate change by the end of the century.

The Paris Climate Agreement’s goal of limiting global warming this century to 3.6 degrees Fahrenheit compared to pre-industrial temperatures was set in December 2015.

It called on countries to take action to reduce greenhouse gas emissions to prevent the most extreme climate change scenarios that scientists predicted at a time when temperatures could rise to 9 degrees Fahrenheit.

However, a new study from the University of Colorado at Boulder, which examined the latest data on emission levels, found that extreme temperatures that would lead to a sharp increase in the number of extreme weather events and sea level rise are no longer likely.

The researchers found that the extreme scenarios and projections of rising temperatures were based on outdated data from 15 years ago, which did not take into account recent efforts to reduce emissions and the transition to renewable energy sources.

They said temperatures were likely to rise by no more than 4 degrees Fahrenheit by 2100, and the 3.6F target was “still within reach” if emissions cuts continued.

They warned that a temperature rise of 3.6 degrees Fahrenheit would still cause “significant damage to the planet” as it was the global average, with some parts of the world “much warmer” and others colder.

According to a new study that shows that efforts to reduce emissions help keep warnings under control, the world is unlikely to reach the "worst-case scenario" of climate change by the end of the century. Solar array in Fort Hunter, California

According to a new study that shows that efforts to reduce emissions help keep warnings under control, the world is unlikely to reach the “worst-case scenario” of climate change by the end of the century. Solar array in Fort Hunter, California

The new study, published in the journal Environmental Research Letters, examined the most recent data on global emissions and created new models to predict likely climate change scenarios over the next 78 years.

They found that by 2100, temperatures were likely to be 3.6 to 5.4 °F higher than pre-industrial levels, averaging 3.96 °F.

“This is cautiously optimistic good news about where the world is today compared to where we thought we might be,” said lead author Roger Pielke Jr., a professor of environmental studies.

“The two-degree target from Paris remains within reach,” he added, thanks to countries’ efforts to reduce emissions.

Almost every country on Earth signed the Paris Climate Agreement in 2015, seeking to keep emissions below 3.6F but trying to keep them below 2.7F.

While the upper target is “within reach,” it will still require significant effort, including leaving unexplored fossil fuel reserves in the ground rather than developing them.

To predict what impact emissions will have on future global temperatures, researchers are creating scenarios.

These are projections of how the future might evolve, based on factors such as projected greenhouse gas emissions and various possible climate policies.

The Paris Climate Agreement's goal of limiting global warming this century to 3.6 degrees Fahrenheit compared to pre-industrial temperatures was set in December 2015.

The Paris Climate Agreement’s goal of limiting global warming this century to 3.6 degrees Fahrenheit compared to pre-industrial temperatures was set in December 2015.

KEY FINDINGS FROM THE CLIMATE SCENARIO STUDY

The researchers found that the world is not far from the 3.6F global climate change target set under the Paris Agreement in 2016.

Temperature projections for 2100 are between 3.6 and 5.4 degrees Fahrenheit, an average of 3.96 degrees Fahrenheit above pre-industrial levels.

These are temperature changes caused by human activity.

Previous studies have used older data dating back to 2005 that did not include information on real efforts to reduce carbon emissions.

This includes steps to transition to renewables, lower levels of fossil fuel extraction, and carbon capture efforts to remove CO2.

That means worst-case scenario predictions, including a 9-degree Fahrenheit temperature rise that would lead to devastating sea level rise, new wildfires, drought and global flooding, are no longer plausible.

The team says a 3.6-degree Fahrenheit temperature rise will still put a significant strain on the planet, and countries need to work to ensure it doesn’t exceed 2.7 degrees Fahrenheit, but that will require sweeping changes.

They called for more regular updating of models to be used in climate change projections and reports.

The most commonly used scenarios, called representative concentration pathways (RCPs), have been developed by the IPCC since 2005.

Subsequent Common Socioeconomic Pathways (SSPs) since 2010 have been conceived as an update. These “pathways” consist of hundreds of scenarios, of which about 11 are used to inform IPCC climate reports.

Pielke and his colleagues compared the scenarios used in the IPCC reports with projected rates of growth in fossil fuel and carbon dioxide emissions from industry in 2005-2050, which were most consistent with real-world observations for 2005-2020.

Comparing the scenarios with projections of real carbon emissions gave them new insights into how plausible the projections were.

They found that out of more than 1100 scenarios, there were between 100 and 500 that most closely matched emission projections.

These scenarios show what future options are likely if current trends continue, and also take into account climate policies adopted or promised by countries to reduce carbon emissions.

While their study shows that the most extreme scenarios are unlikely, and we may reach the goal of 3.6 degrees Fahrenheit warming, there may also be more optimistic or pessimistic options for the future.

“Since we haven’t updated our [IPCC] scenarios [for many years], there are also some future options that are likely but not yet foreseen,” Pilke Jr. said.

However, their findings add to other studies that suggest we are no longer moving towards the worst-case scenario of climate change, including the IPCC Sixth Assessment Report, published last year.

The reason for the sudden “good news” is that the models and scenarios used for forecasting are becoming obsolete, and most of them were developed more than a decade ago.

“A lot has happened since then,” said Matthew Burgess, co-author of this new study.

“For example, renewable energy has become more affordable and therefore more common faster than expected,” he added.

These rapid changes are reflected in scenarios developed by the IEA, a Paris-based intergovernmental organization that provides annual updates.

Climate scenarios also tend to overestimate economic growth, especially in poorer countries, according to Burgess, an assistant professor of environmental studies.

The team explained that the 2010 scenarios were supposed to serve as an update to the assumptions made in the original 2005 scenarios, but they were not widely accepted, and older scenarios are still used by scientists.

The researchers found that the extreme scenarios and projections of rising temperatures were based on outdated data from 15 years ago, which did not take into account recent efforts to reduce emissions and the transition to renewable energy sources.

The researchers found that the extreme scenarios and projections of rising temperatures were based on outdated data from 15 years ago, which did not take into account recent efforts to reduce emissions and the transition to renewable energy sources.

NOT BUSINESS AS USUAL: RESEARCH SHOWS MODELS DON’T USE REAL DATA

When forecasting climate change, scenarios are created to predict the levels of carbon emissions in the future and their impact on global average temperatures.

The study found that all baseline scenarios that are “normal” without changes made by governments exceed projected emission levels.

This was compared to the projections of rising carbon emissions in 2005-2050 made by the International Energy Agency using real data.

This suggests that climate research and policy are currently overly focused on implausibly pessimistic future scenarios, the researchers warn.

“Relying on implausible scenarios can be misleading in policy analysis,” said study leader Roger Pielke Jr.

“For example, the use of baseline scenarios that overestimate short-term emissions requires the assumption that carbon removal technologies need to be deployed unnecessaryly in late 21st century policy scenarios.”

A commonly used “worst-case” scenario known as RCP8.5, which is named after 8.5 watts per square meter, a measure of solar radiation, predicts an increase of 7.2 to 9 F (4 to 5 C) by 2100. the script is now considered unlikely and outdated.

“It’s hard to overstate how much [climate] studies have focused on four- and five-degree scenarios, one of which is RCP 8.5. And every year they look less and less believable,” Burgess said.

According to the authors, relying not only on outdated scenarios, but also on scenarios that are no longer plausible, for research and policy is of great importance for how we think, act and spend money on climate change issues.

The study found that all baseline scenarios that are “normal” without changes made by governments exceed projected emission levels.

This was compared to the projections of rising carbon emissions in 2005-2050 made by the International Energy Agency using real data.

This suggests that climate research and policy are currently overly focused on implausibly pessimistic future scenarios, the researchers warn.

“Relying on implausible scenarios can be misleading in policy analysis,” said study leader Roger Pielke Jr.

“For example, the use of baseline scenarios that overestimate short-term emissions requires the assumption that carbon removal technologies need to be unnecessarily deployed in late 21st century policy scenarios.

“It is also noteworthy that the vast majority of scenarios that project a future into 2100 do not meet our simple plausibility criteria by 2020, even though they have been developed in recent years and decades.”

“It is imperative that these scripts be updated more frequently. Researchers can use the 2005 scenario, but we need a 2022 perspective,” Pilke Jr. added.

“You’re going to have better politics if you have a more accurate understanding of the problem, whatever the political implications are for either side.”

The authors emphasize that warming of 3.6 degrees Fahrenheit (2 degrees Celsius) will still cause huge damage to the planet, and now is not the time for complacency.

“We’re getting closer to our goal of two degrees, but we definitely still have a lot of work to do if we’re going to get to 1.5,” Burgess said.

The study was published in the journal Environmental Research Letters.

PARIS AGREEMENT: GLOBAL AGREEMENT TO LIMIT TEMPERATURE INCREASES THROUGH CARBON REDUCTION TARGETS

The Paris Agreement, first signed in 2015, is an international agreement to control and limit climate change.

It hopes to keep the rise in average global temperature below 2 °C (3.6 °F) “and continue efforts to limit the temperature rise to 1.5 °C (2.7 °F).”

It appears that the more ambitious goal of limiting global warming to 1.5 °C (2.7 °F) may be more important than ever, according to a previous study that argues that 25 percent of the world could face a significant increase in dry conditions.

The Paris Agreement on Climate Change has four main objectives in relation to reducing emissions:

1) The long-term goal is to keep the increase in global average temperature well below 2°C compared to pre-industrial levels.

2) Aim to limit the increase to 1.5 °C, as this will significantly reduce the risks and effects of climate change.

(3) Governments agreed on the need to reach the peak of global emissions as soon as possible, recognizing that this would take longer for developing countries.

4) Then undertake rapid reductions in accordance with the best available science.

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