Final answer:
It is true that cerebral edema can increase if carbon dioxide levels are allowed to increase, as this leads to blood vessel dilation and altered diffusion rates which contribute to fluid accumulation in brain tissues.
Step-by-step explanation:
The statement that cerebral edema will increase if carbon dioxide levels are allowed to increase is true. Higher levels of carbon dioxide in the blood can lead to increased acidity as CO2 is converted into carbonic acid or bicarbonate. This process can cause vasodilation, which in the case of cerebral blood vessels can lead to increased fluid movement into brain tissues, contributing to cerebral edema. Additionally, an increase in CO2 reduces the rate of diffusion into the blood by reducing the difference in partial pressures between the air and the blood, which can worsen the edema.