sperm count decline

Frequently asked questions on the new sperm count decline study

Sperm counts are declining everywhere — the implications are huge.

What is happening with sperm counts?


This study shows, for the first time, that sperm counts are declining everywhere, not only in North America, Europe, Australia and New Zealand, which was shown previously, but also in South America, Asia and Africa. This new analysis found that sperm count globally dropped by more than 50% between 1973 and 2018, and that the decline is accelerating: Since 1972, sperm count has dropped by about 1% each year. Since 2000, the annual decrease has been, on average, more than 2.6%.

What do lower sperm counts this mean for our health?

This accelerated decrease in global sperm counts means more people will need to use assisted reproduction to get pregnant. These findings imply more than decreased fertility; lower sperm counts are linked to more disease later in life (cardiovascular disease, diabetes and reproductive cancers) and a shorter life expectancy.

Why are sperm counts declining?

The decline is too rapid to be due to genetic causes alone. Some risk factors for lower sperm counts have to do with lifestyle; smoking, obesity, stress and binge drinking. In addition, environmental chemicals — particularly those that can alter the body’s hormones called endocrine disrupting chemicals (pesticides, phthalates, BPA, PFAS chemicals and others) — have been shown to reduce sperm counts and quality and are likely contributing to this decline.

What can be done about lower sperm counts?

While scientists continue to tease out the causes, men should avoid smoking, a sedentary lifestyle, excessive weight gain, drug and alcohol abuse, and potentially toxic chemicals. This means buying organic food when possible or washing fruits and vegetables that may have pesticide residues. Another good idea is avoiding plastics in food contact materials and personal care and household products that contain phthalates and other endocrine-disrupting compounds.

Read more about the new study: A new analysis shows a “crisis” of male reproductive health

Watch Dr. Shanna Swan discuss the work and implications

A view of a huge solar farm in Brazil with mountain ranges in the background

Brazil’s unique data center boom rides on clean power despite social burden

With a predominantly renewable energy mix, Brazil has become an attractive destination for data centers.

A view of a traffic jam with many cars and red brake lights

The clean energy transition has a grid problem. Here’s how to fix it

If the United States’ electrical grid were a highway, much of it would be clogged with bumper-to-bumper traffic.

A view of a row of oil pump jacks with a beautiful sunset in the background

The world inches closer to catastrophic climate events

Scientists have long warned that the world will experience more intense extreme weather events like heat waves, storms, floods and droughts as long as we continue to use gas, oil and coal at our current pace.
An aerial view of a town surrounded by green trees with a huge storm in the distance

Even meteorologists are baffled by the Midwestern tornado season

More than 200 tornadoes have hit Illinois this year. Here's how the twisters form, and how climate change might be influencing them.
A view of two nuclear towers at sunset

Why nuclear, why New Hampshire, why now?

Dependence on natural gas is a major reason New Hampshire’s electric bills — and those in other New England states — often rank among the highest in the nation.

A linen dress on a woman in a field of wildflowers; she is holding a woven basket with plants inside

Fashion’s climate opportunity: Can we dress our way towards change?

Fashion's climate impact isn't a question of what our clothes are made from, but of a system built around encouraging us to consume more.

From our Newsroom
Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

Multiple Houston-area oil and gas facilities that have violated pollution laws are seeking permit renewals

One facility has emitted cancer-causing chemicals into waterways at levels up to 520% higher than legal limits.

Regulators are underestimating health impacts from air pollution: Study

Regulators are underestimating health impacts from air pollution: Study

"The reality is, we are not exposed to one chemical at a time.”

Pennsylvania governor Josh Shapiro speaks with the state flag and American flag behind him.

Two years into his term, has Gov. Shapiro kept his promises to regulate Pennsylvania’s fracking industry?

A new report assesses the administration’s progress and makes new recommendations

silhouette of people holding hands by a lake at sunset

An open letter from EPA staff to the American public

“We cannot stand by and allow this to happen. We need to hold this administration accountable.”

wildfire retardants being sprayed by plane

New evidence links heavy metal pollution with wildfire retardants

“The chemical black box” that blankets wildfire-impacted areas is increasingly under scrutiny.

Stay informed: sign up for The Daily Climate newsletter
Top news on climate impacts, solutions, politics, drivers. Delivered to your inbox week days.