Final answer:
IPv6 is the IP addressing scheme that significantly increases the number of available IP addresses by using a 128-bit addressing scheme, in contrast to the 32-bit scheme used by IPv4.
Step-by-step explanation:
The new IP addressing scheme that may increase the number of available IP addresses is IPv6. IPv6, or Internet Protocol version 6, is a protocol developed to address the exhaustion of IP addresses available under the IPv4 protocol. Unlike IPv4, which uses a 32-bit addressing scheme resulting in approximately 4.3 billion unique addresses, IPv6 uses a 128-bit addressing scheme. This expansion allows for a virtually unlimited number of unique addresses, ensuring that the growing number of devices connected to the internet can have a unique IP address. The other options, such as CIDR (Classless Inter-Domain Routing), subnetting, and ARP (Address Resolution Protocol), are related to IP addressing but do not directly increase the total number of available IP addresses to the extent that IPv6 does.