Updated Jun 4, 2018

Why climate change hits poorest countries hardest

It's long been said that climate change will be felt earliest and most severely in the poor nations of the world that contributed the least to the problem. A recent study, along with illuminating data from a new World Bank Report, show how this is the case.

Change in extremely hot days by the end of the century based on two emissions scenarios. Data: World Bank Atlas of Sustainable Development Goals, 2018; Adapted from a World Bank report; Map: Harry Stevens/Axios

Why this matters: Solving climate change involves a fundamental mismatch between the countries that emit the most greenhouse gases, and those that stand to suffer the earliest and most from the problem. This is part of the reason of why addressing climate change has been so difficult to solve.

A new study, published in Geophysical Research Letters, provides a new way of understanding why a global average temperature increase above 1.5 degrees Celsius (2.7 degrees Fahrenheit) compared to preindustrial levels would be tough for poor, tropical nations to adapt to.

  • The study uses the concept of a signal-to-noise ratio, factoring in the typical range of temperatures a region is accustomed to.
  • The signal, according to the study, is the local change in average temperatures related to climate change.
  • The noise is how variable the temperature normally is for that region.

Outside the tropics, places have greater year-to-year variability in temperatures, and are more adapted to a wide range of temperatures — from cold conditions to sizzling heat.

  • But in the equatorial regions, where poorer nations tend to be located, society is accustomed to a higher average temperature that has little variability, or low amount of noise, associated with it. Therefore, it wouldn't take much warming to tip the climate outside of the accustomed range, making warming more noticeable.

What they're saying: Study co-author Andrew King, of the ARC Center of Excellence for Climate Extremes and the University of Melbourne in Australia, told Axios that the metric used in the study shows that even the most stringent temperature target under the Paris Climate Agreement would have a major impact in tropical regions by making intolerably hot temperatures far more common.

"The main result is that, in general, it will be the poorest people on the planet who experience the largest shift in their local climate if we go beyond the 1.5 degrees Celsius Paris limit. In the tropics the variability is lower, so the perceptibility of local climate change is higher there."
— King in an email to Axios

The bigger picture: Separate World Bank data released May 24 shows what would happen with heat extremes if there were about 2 degrees Celsius of global warming, and an emissions scenario more consistent with greater than 4 degrees Celsius of warming.

  • In both scenarios, areas closest to the tropics — including some of the most populated places on the planet — would see a marked increase in days with a heat index exceeding 95 degrees Fahrenheit. The heat index combines temperature and humidity, and is used to measure how hot it feels to the human body.

Take note: The world has already warmed by more than 1-degree Celsius compared to the dawn of the industrial era.

Get more stories like this by signing up for our weekly science newsletter, Axios Science. 

Go deeper

There are warning signs that Nevada could be Iowa all over again

Former Sen. Harry Reid (D) lines up to cast an early vote for the upcoming Nevada Democratic presidential caucus. Photo: Ethan Miller/Getty Images

The alarms are increasingly sounding over Nevada's Democratic caucus, which is just five days away.

Why it matters: Similar issues to the ones that plagued Iowa's caucus seem to be rearing their ugly heads, the WashPost reports.

China tries to contain coronavirus, as Apple warns of earnings impact

Data: The Center for Systems Science and Engineering at Johns Hopkins, the CDC, and China's NHC; Note: China refers to mainland China and the Diamond Princess is the cruise ship offshore Yokohama, Japan. Map: Danielle Alberti/Axios

As China pushes to contain the spread of the novel coronavirus — placing around 780 million people under travel restrictions, per CNN — the economic repercussions continue to be felt globally as companies like Apple warn of the impact from the lack of manufacturing and consumer demand in China.

The big picture: COVID-19 has now killed at least 1,775 people and infected more than 70,000 others, mostly in mainland China. There are some signs that new cases are growing at a slower rate now, although the World Health Organization said Monday it's "too early to tell" if this will continue.

Go deeperArrowUpdated 4 hours ago - Health

Apple will miss quarterly earnings estimates due to coronavirus

Apple CEO Tim Cook

Apple issued a rare earnings warning on Monday, saying it would not meet quarterly revenue expectations due to the impact of the coronavirus, which will limit iPhone production and limit product demand in China.

Why it matters: Lots of companies rely on China for production, but unlike most U.S. tech companies, Apple also gets a significant chunk of its revenue from sales in China.