Radiation

"Radiation sickness" (Acute Radiation Syndrome) is a severe medical condition caused by exposure to high doses of ionizing radiation, such as the radiation from a nuclear accident or atomic blast. Climate change does not cause radiation sickness.

However, climate change is actively influencing our exposure to solar ultraviolet (UV) radiation, which is a type of non-ionizing radiation. This is a very serious public health issue in New Zealand, directly impacting the rates of UV-induced diseases.

Here is a summary of how climate change is impacting UV radiation and related diseases for people living in New Zealand.

The Baseline: Why New Zealand is Vulnerable

Even without climate change, New Zealanders face extreme levels of summertime UV radiation. This is due to a combination of factors: the Earth's orbit brings the Southern Hemisphere closer to the sun during our summer, our atmosphere has less pollution to block UV rays, and we are geographically close to the Antarctic ozone hole. As a result, New Zealand consistently records the highest rates of skin cancer (particularly melanoma) in the world.

How Climate Change Worsens UV Exposure

Climate change amplifies the risks of UV-related diseases in New Zealand through two main pathways:

1. Delayed Ozone Recovery: The ozone layer acts as the Earth's natural sunscreen. While the primary cause of ozone depletion was CFCs (which have been phased out), climate change and increasing greenhouse gases alter atmospheric circulation and temperatures in the stratosphere. Scientists warn that these climate-driven changes may delay the full recovery of the ozone layer, meaning higher levels of UV radiation will continue to reach ground level in New Zealand for longer than initially expected.

2. Behavioral Changes (The "Warmer Weather" Effect): As climate change drives up average global and regional temperatures, New Zealand is experiencing longer, hotter summers and milder winters. Warmer weather encourages people to spend more time outdoors and wear lighter, more skin-exposing clothing. This prolonged behavioral exposure is one of the most significant ways climate change increases the risk of UV damage.

The Health Impacts (UV-Induced Diseases)

The combination of intense UV radiation and increased exposure time leads to a higher incidence of specific diseases in New Zealand:

• Melanoma: The deadliest form of skin cancer. Because UV radiation reaches the skin so intensely in New Zealand, cellular DNA damage can begin within minutes of unprotected exposure.

• Non-Melanoma Skin Cancers: Basal cell carcinoma and squamous cell carcinoma are highly prevalent in New Zealand and are directly linked to cumulative sun exposure over a person's lifetime.

• Eye Damage (Cataracts): Prolonged UV exposure is a leading cause of cataracts, which cloud the lens of the eye and impair vision. Rising UV levels translate to higher risks of long-term ocular damage.

• Immune System Suppression: High levels of UV radiation can suppress the skin’s local immune system, which not only aids in the development of skin cancers but can also make the body more susceptible to certain infections.

While we don't have to worry about radiation sickness from a changing climate, the rising temperatures and shifting atmospheric conditions mean that strict sun safety—using broad-spectrum sunscreen, wearing protective clothing, and seeking shade—is more vital for New Zealanders now than ever before.